Question

Graph the following lines and write the equation in slope-intercept form. With y intercept of −3 and an x intercept of −4.5.

Answer 1

`y=-(2)/(3)x-3`

Explanation:

To write the equation of a line we need 2 points. We know:

• If the y-intercept of the line is -3 then the point is (0,-3).

• If the x-intercept of the line is -4.5 then the point is (-4.5,0).

Using these two point, we will find the slope and then substitute it into the point slope form
`y-y_1=m(x-x_1)` with a point.

Slope:
`m=(0--3)/(-4.5-0)=(0+3)/(-4.5)=(3)/(-4.5)=-0.6667`

This decimal is -2/3. We will now substitute -2/3 and (0,-3) into the point slope form.

`y--3=-(2)/(3)(x-0)\\y+3=-(2)/(3)(x)\\y+3=-(2)/(3)x\\y=-(2)/(3)x-3`