IndietroCollege Algebra: Linear Equations, Slope, and Intercepts Study Guide
Guida di studio - Note intelligenti
Appunti personalizzati basati sui tuoi materiali, ampliati con definizioni chiave, esempi e contesto.
Q13. Rewrite in slope-intercept form. Then state the zero (x-intercept) of the function.
Background
Topic: Linear Equations – Slope-Intercept Form and Intercepts
This question tests your ability to manipulate a linear equation into slope-intercept form () and to find the x-intercept (also called the zero) of the function.
Key Terms and Formulas:
Slope-intercept form: , where is the slope and is the y-intercept.
x-intercept (zero): The value of when .
Step-by-Step Guidance
Start with the given equation: .
Rearrange the equation to solve for in terms of (get $y$ by itself on one side).
Once in form, identify the slope and y-intercept.
To find the x-intercept, set in your equation and solve for .
Try solving on your own before revealing the answer!
Final Answer:
Rewriting in slope-intercept form:
Subtract from both sides:
Multiply both sides by :
Slope-intercept form:
To find the x-intercept, set :
The x-intercept (zero) is .
Q15. Which equation represents a line with slope and y-intercept $2$?
Background
Topic: Linear Equations – Identifying Slope and Intercept
This question tests your ability to recognize the equation of a line in slope-intercept form () given a specific slope and y-intercept.
Key Terms and Formulas:
Slope-intercept form:
Slope (): The coefficient of
y-intercept (): The constant term
Step-by-Step Guidance
Recall that the equation of a line with slope and y-intercept is .
Plug in and into the formula.
Compare your result to the answer choices to find the matching equation.
Try solving on your own before revealing the answer!
Final Answer:
Plugging in the values, the equation is:
This matches answer choice B.
Q16. Which equation is parallel to and passes through ?
Background
Topic: Parallel Lines and Point-Slope Form
This question tests your understanding of parallel lines (same slope) and writing the equation of a line through a given point.
Key Terms and Formulas:
Slope of a line: For , slope is
Parallel lines: Have the same slope
Point-slope form:
Step-by-Step Guidance
Find the slope of by rewriting in slope-intercept form or using .
Since parallel lines have the same slope, use this slope for your new line.
Use the point-slope form with the point and the slope you found.
Simplify to slope-intercept form () and compare to the answer choices.
Try solving on your own before revealing the answer!
Final Answer:
The slope of is .
Using point-slope form:
Simplifying:
This matches answer choice A: .
Q17. Write the equation of the line that passes through and has slope $2$ in point-slope form and slope-intercept form.
Background
Topic: Writing Equations of Lines
This question tests your ability to use point-slope and slope-intercept forms to write the equation of a line given a point and a slope.
Key Terms and Formulas:
Point-slope form:
Slope-intercept form:
Step-by-Step Guidance
Use the point-slope form with , , .
Write the equation in point-slope form: .
Expand and simplify to get the equation in slope-intercept form ().
Try solving on your own before revealing the answer!
Final Answer:
Point-slope form:
Slope-intercept form:
Q18. The equation is given. Find its slope, x-intercept, and y-intercept.
Background
Topic: Linear Equations – Slope and Intercepts
This question tests your ability to find the slope, x-intercept, and y-intercept of a line given in standard form.
Key Terms and Formulas:
Standard form:
Slope:
x-intercept: Set and solve for
y-intercept: Set and solve for
Step-by-Step Guidance
Identify , , in the equation .
Find the slope using .
To find the x-intercept, set and solve for .
To find the y-intercept, set and solve for .
Try solving on your own before revealing the answer!
Final Answer:
Slope:
x-intercept: (when )
y-intercept: (when )