Question

I need help. I dont know how to solve this.

Answer 1

(-18,0) x-intercept

(0,-6) y-intercept

Explanation:

We are given this is a line.

Slope-intercept form of a line is y=mx+b where m is slope and b is y-intercept.

To find the slope we will need to compute
`(y_2-y_1)/(x_2-x_1)`

where
`(x_1,y_1)` and
`(x_2,y_2)` are points on your line.

The way I like to do this is line up the points vertically and subtract then put 2nd difference over 1st difference.

Like so:

(-15 , -1)

-(-9 , -3)

-------------

-6 2

So the slope is 2/-6 or -1/3.

The equation we have so far without knowing the y-intercept,b, is

y=(-1/3)x+b

Now to find b use one of the points on your line. You get to chose this.

How about (-3,-5)? Sure that's fine.

If (x,y)=(-3,-5) then we have -5=(-1/3)(-3)+b.

Let's solve this for b.

-5=(-1/3)(-3)+b

-5=1+b

Subtract 1 on both sides:

-5-1=b

-6=b

The equation is y=(-1/3)x+-6 or y=(-1/3)x-6.

So b represented the y-intercept so the y-intercept is -6 or (0,-6).

To find the x-intercept, you set y=0 and solve for x:

y=(-1/3)x-6

0=(-1/3)x-6

Add 6 on both sides:

6=(-1/3)x

Multiply both sides by -3:

-18=x

The x-intercept is (-18,0).