Question

Find the x- and y-intercepts of the line
(-6.-6), (2, -4)
The x-intercept is

Answer 1

x-int = 18

y-int = -9/2

Explanation:

Use slope-intercept form y=mx + b

To find the slope, substitute the two points into the slope formula and solve.

`m  = (y2 - y1)/(x1 - x1) \\m  = (-4 - (-6))/(2 - (-6)) \\m = (2)/(8)\\m= (1)/(4)`

Substitute a random point (2,-4) and m=1/4 into slope-intercept form

y = mx+b

-4 = 1/4 (2) + b

-4 = 2/4 + b

-4 = 1/2 + b

Isolate b to solve

b = -4 - 1/2

b = -8/2 - 1/2

b = -9/2 <= this is the y-intercept

b is the y-intercept in slope-intercept form

Substitute b= -9/2 and m=1/4 to get the equation of the line.

y = 1/4 x - 9/2

Substitute y for 0 to find the x intercept

y = 1/4 x - 9/2

0 = 1/4 x - 9/2

9/2 = 1/4 x

x = (9/2) / (1/4)

x = (9/2) X (4/1)

x = 36/2

x = 18