Question

This table gives a few (x,y) pairs of a line in the coordinate plane

what is the y-intercept of of the line?

Answer 1

y intercept is -23

Explanation:

Here we are given three coordinates and are asked to find y intercept of the line passing through these points.

We thus find the equation of this line by two point form

the form says

(y-y1)/(x-x1) = (y2-y1)/(x2-x1)

Here (x1,y1) = ( -36 , 1 )

and (x2,y2) = ( 13,-54)

Substituting the values we get

(y-1)(x+36)=(1-13)/(-36-(-54))

(y-1)(x+36)=(-12)/(-36+54)

(y-1)(x+36)=(-12)/(18)

y-1=-2/3 ( x+36)

In order to determine the y intercept we are required to leep x = 0 in above equation and solve for y

y-1 = -2/3 (0+36 )

y-1= (-2/3) x (36 )

y-1 = -2 x 12

y-1 = -24

adding 1 on both hand sides

y = -24 +1

y=-23