0. Review of Algebra

In Exercises 121–128, write each English phrase as an algebraic expression. Then simplify the expression. Let x represent the number. The difference between the product of six and a number and negative two times the number

In Exercises 1–6, find all numbers that must be excluded from the domain of each rational expression. (x+5)/(x²−25)

Perform the indicated operation.

$\left(x^3+3x^2-7x\right)+2\left(x^3-5x^2+9x+4\right)$

Perform the indicated operation.

$\left(-2x^4+10x^3+6x-3\right)-\left(x^4-7x^2+8x+5\right)$

Evaluate each algebraic expression for the given value or value(s) of the variable(s). 3+6(x-2)³ for x = 4

Find all numbers that must be excluded from the domain of each rational expression. 7/(x−3)

In Exercises 5–8, find the degree of the polynomial. 3x²−5x+4

In Exercises 5–8, find the degree of the polynomial. x²−4x³+9x−12x⁴+63

In Exercises 7–14, simplify each rational expression. Find all numbers that must be excluded from the domain of the simplified rational expression. (3x−9)/(x²−6x+9)

In Exercises 9–14, perform the indicated operations. Write the resulting polynomial in standard form and indicate its degree. (−6x³+5x²−8x+9)+(17x³+2x²−4x−13)

In Exercises 9–14, perform the indicated operations. Write the resulting polynomial in standard form and indicate its degree. (17x³−5x²+4x−3)−(5x³−9x²−8x+11)