Question

Write the slope-intercept equation of the line through
the coordinates (4,5) and (-4,-3).

Answer 1

y = 1/4x + 4

Explanation:

Knowledge Needed

Slope: The amount the y-value changes on a constant line when the x-value increases by 1.

Slope Formula:

`(y_2-y_1)/(x_2-x_1)`

y-intercept: When the line has a x-value of , or when it intersects the y-axis.

Slope-Intercept Form: y = mx+b

m is slope, b is y-intercept.

Leave y and x as variables so you can graph it.

Question

First, plug the points into the slope formula.

`(3-5)/(-4-4)`

`(-2)/(-8)`

1/4

y = 1/4x + b

Solve for b:

Use any of the 2 points to plug back in. I'll use (4,5).

We have: y = 1/4x + b

(5) = 1/4(4) + b

5 = 1 + b

5 - 1= 1 - 1 + b

b = 4

y = 1/4x + 4