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Precalculus Review: Exponents, Polynomials, Functions, Inverses, and Radicals

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Q1. Simplify the exponential expression: \( \frac{-36x^{13}y^{13}z^7}{4x^8y^6z^6} \)

Background

Topic: Properties of Exponents and Simplifying Rational Expressions

This question tests your ability to simplify expressions involving exponents by applying the quotient rule and combining like terms.

Key Terms and Formulas

  • Quotient Rule: \( \frac{a^m}{a^n} = a^{m-n} \)

  • Product Rule: \( a^m \cdot a^n = a^{m+n} \)

  • Negative Exponent Rule: \( a^{-n} = \frac{1}{a^n} \)

Step-by-Step Guidance

  1. Break the expression into separate fractions for each variable: \( \frac{-36}{4} \cdot \frac{x^{13}}{x^8} \cdot \frac{y^{13}}{y^6} \cdot \frac{z^7}{z^6} \).

  2. Simplify the coefficients: \( \frac{-36}{4} \).

  3. Apply the quotient rule to each variable: subtract the exponents in the numerator and denominator for each variable.

  4. Write the simplified expression, but do not combine the final terms yet.

Try solving on your own before revealing the answer!

Final Answer: \( -9x^5y^7z \)

We simplified the coefficients to -9, and for each variable, subtracted the exponents: \( x^{13-8} = x^5 \), \( y^{13-6} = y^7 \), \( z^{7-6} = z^1 \).

Q2. Simplify the exponential expression: \( \frac{35x^{11}y^{15}}{5x^{10}y^{-10}} \)

Background

Topic: Properties of Exponents and Simplifying Rational Expressions

This question tests your ability to simplify expressions with positive and negative exponents.

Key Terms and Formulas

  • Quotient Rule: \( \frac{a^m}{a^n} = a^{m-n} \)

  • Negative Exponent Rule: \( a^{-n} = \frac{1}{a^n} \)

Step-by-Step Guidance

  1. Separate the coefficients and variables: \( \frac{35}{5} \cdot \frac{x^{11}}{x^{10}} \cdot \frac{y^{15}}{y^{-10}} \).

  2. Simplify the coefficients: \( \frac{35}{5} \).

  3. Apply the quotient rule to the exponents for x and y. Remember, subtract the denominator exponent from the numerator exponent.

  4. For y, subtracting a negative exponent is the same as adding: \( 15 - (-10) \).

Try solving on your own before revealing the answer!

Final Answer: \( 7x y^{25} \)

The coefficients simplify to 7, \( x^{11-10} = x^1 \), and \( y^{15-(-10)} = y^{25} \).

Q3. Simplify the exponential expression: \( \left( \frac{2x^3y^4}{z^4} \right)^2 \)

Background

Topic: Properties of Exponents (Power of a Quotient and Power of a Power)

This question tests your ability to apply the power rule to both the numerator and denominator of a fraction.

Key Terms and Formulas

  • Power of a Product: \( (ab)^n = a^n b^n \)

  • Power of a Power: \( (a^m)^n = a^{mn} \)

  • Power of a Quotient: \( \left( \frac{a}{b} \right)^n = \frac{a^n}{b^n} \)

Step-by-Step Guidance

  1. Apply the power to each part of the numerator and denominator: \( (2)^2, (x^3)^2, (y^4)^2, (z^4)^2 \).

  2. Use the power of a power rule to simplify each exponent: multiply the exponents.

  3. Write the new expression with the simplified exponents.

  4. Combine all terms into a single fraction.

Try solving on your own before revealing the answer!

Final Answer: \( \frac{4x^6y^8}{z^8} \)

Each part is squared: 2 becomes 4, \( x^3 \) becomes \( x^6 \), \( y^4 \) becomes \( y^8 \), and \( z^4 \) becomes \( z^8 \).

Q4. Simplify the exponential expression: \( \left( \frac{-12x^{10}y^7}{6x^{14}y^{-2}} \right)^3 \)

Background

Topic: Properties of Exponents (Power of a Quotient, Negative Exponents)

This question tests your ability to simplify a complex rational expression with exponents, including negative exponents, and then raise the result to a power.

Key Terms and Formulas

  • Quotient Rule: \( \frac{a^m}{a^n} = a^{m-n} \)

  • Negative Exponent Rule: \( a^{-n} = \frac{1}{a^n} \)

  • Power of a Power: \( (a^m)^n = a^{mn} \)

  • Power of a Quotient: \( \left( \frac{a}{b} \right)^n = \frac{a^n}{b^n} \)

Step-by-Step Guidance

  1. Simplify inside the parentheses first: divide the coefficients and apply the quotient rule to each variable.

  2. For y, remember to subtract the denominator exponent (which is negative) from the numerator exponent.

  3. Write the simplified base expression before applying the cube (power of 3).

  4. Raise each part of the simplified base to the third power using the power of a power rule.

Try solving on your own before revealing the answer!

Final Answer: \( \frac{-8y^{27}}{x^{12}} \)

After simplifying inside the parentheses and applying the cube, the result is \( -8y^{27}/x^{12} \).

Q5. Perform the indicated operation and write the resulting polynomial in standard form: \( (8x^6 - 8x^5 - 4x^4 - 1) - (5x^6 - 3x^5 + 6x^4 + 3) \)

Background

Topic: Polynomial Operations (Subtraction and Combining Like Terms)

This question tests your ability to subtract polynomials and combine like terms, then write the result in standard form (descending powers of x).

Key Terms and Formulas

  • Standard Form: Write terms in order from highest to lowest degree.

  • Combine Like Terms: Add or subtract coefficients of terms with the same variable and exponent.

Step-by-Step Guidance

  1. Distribute the negative sign to each term in the second polynomial.

  2. Write out all terms, grouping like terms together (same powers of x).

  3. Add or subtract the coefficients for each group of like terms.

  4. Arrange the resulting polynomial in standard form.

Try solving on your own before revealing the answer!

Final Answer: \( 3x^6 - 5x^5 - 10x^4 - 4 \)

After distributing and combining like terms, the polynomial is written in standard form.

Q6. Perform the indicated operation and write the resulting polynomial in standard form: \( (7x^5 + 9x^2 + 5) - (3x^5 + 5x^2 - 5) \)

Background

Topic: Polynomial Operations (Subtraction and Combining Like Terms)

This question tests your ability to subtract polynomials and combine like terms.

Key Terms and Formulas

  • Combine Like Terms: Add or subtract coefficients of terms with the same variable and exponent.

  • Standard Form: Write terms in order from highest to lowest degree.

Step-by-Step Guidance

  1. Distribute the negative sign to each term in the second polynomial.

  2. Group like terms together (same powers of x).

  3. Add or subtract the coefficients for each group of like terms.

  4. Write the resulting polynomial in standard form.

Try solving on your own before revealing the answer!

Final Answer: \( 4x^5 + 4x^2 + 10 \)

After combining like terms, the polynomial is in standard form.

Q7. Find the product: \( (x + 4)(3x^2 + 6x + 7) \)

Background

Topic: Polynomial Multiplication (Distributive Property/FOIL)

This question tests your ability to multiply a binomial by a trinomial using the distributive property.

Key Terms and Formulas

  • Distributive Property: \( a(b + c) = ab + ac \)

  • Combine Like Terms: Add coefficients of terms with the same degree.

Step-by-Step Guidance

  1. Multiply each term in the first factor (x and 4) by each term in the second factor (3x^2, 6x, 7).

  2. Write out all resulting terms.

  3. Group like terms (same powers of x) together.

  4. Add the coefficients of like terms, but do not combine the final result yet.

Try solving on your own before revealing the answer!

Final Answer: \( 3x^3 + 18x^2 + 31x + 28 \)

After distributing and combining like terms, the product is a cubic polynomial.

Q8. Find the product: \( (6x - 1)(x^2 - 4x + 1) \)

Background

Topic: Polynomial Multiplication (Distributive Property)

This question tests your ability to multiply a binomial by a trinomial and combine like terms.

Key Terms and Formulas

  • Distributive Property: \( a(b + c) = ab + ac \)

  • Combine Like Terms: Add coefficients of terms with the same degree.

Step-by-Step Guidance

  1. Multiply each term in the first factor (6x and -1) by each term in the second factor (x^2, -4x, 1).

  2. Write out all resulting terms.

  3. Group like terms (same powers of x) together.

  4. Add the coefficients of like terms, but do not combine the final result yet.

Try solving on your own before revealing the answer!

Final Answer: \( 6x^3 - 25x^2 + 10x - 1 \)

After distributing and combining like terms, the product is a cubic polynomial.

Q9. Find the product: \( (x - 12)(x^2 + 4x - 7) \)

Background

Topic: Polynomial Multiplication (Distributive Property)

This question tests your ability to multiply a binomial by a trinomial and combine like terms.

Key Terms and Formulas

  • Distributive Property: \( a(b + c) = ab + ac \)

  • Combine Like Terms: Add coefficients of terms with the same degree.

Step-by-Step Guidance

  1. Multiply each term in the first factor (x and -12) by each term in the second factor (x^2, 4x, -7).

  2. Write out all resulting terms.

  3. Group like terms (same powers of x) together.

  4. Add the coefficients of like terms, but do not combine the final result yet.

Try solving on your own before revealing the answer!

Final Answer: \( x^3 - 8x^2 - 55x + 84 \)

After distributing and combining like terms, the product is a cubic polynomial.

Q10. Find the product: \( (x - 7y)(x + 4y) \)

Background

Topic: Multiplying Binomials (FOIL Method)

This question tests your ability to multiply two binomials, including terms with different variables.

Key Terms and Formulas

  • FOIL Method: First, Outer, Inner, Last for binomial multiplication.

  • Combine Like Terms: Add coefficients of terms with the same variables.

Step-by-Step Guidance

  1. Multiply the first terms: x * x.

  2. Multiply the outer terms: x * 4y.

  3. Multiply the inner terms: -7y * x.

  4. Multiply the last terms: -7y * 4y.

  5. Combine like terms (if any) to simplify the expression.

Try solving on your own before revealing the answer!

Final Answer: \( x^2 - 3xy - 28y^2 \)

After multiplying and combining like terms, the result is a quadratic in x and y.

Q11. Find the product: \( (9x - 5y)^2 \)

Background

Topic: Squaring a Binomial (Special Products)

This question tests your ability to expand the square of a binomial using the formula \( (a - b)^2 = a^2 - 2ab + b^2 \).

Key Terms and Formulas

  • Square of a Binomial: \( (a - b)^2 = a^2 - 2ab + b^2 \)

  • Combine Like Terms: Add coefficients of terms with the same variables.

Step-by-Step Guidance

  1. Write the expression as \( (9x - 5y)(9x - 5y) \).

  2. Multiply each term in the first binomial by each term in the second binomial.

  3. Combine like terms to simplify the expression.

  4. Write the result in standard form.

Try solving on your own before revealing the answer!

Final Answer: \( 81x^2 - 90xy + 25y^2 \)

After expanding and combining like terms, the result is a quadratic in x and y.

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