Question

Which equation is in slope-intercept form & represents a line with slope 3 through the point (9, -4)?
A) y = 3x + 21
B) -3x + y = -31
C) y = 3x - 31
D) -3x + y = 21

Answer 1

I know that B & D aren't possibilities.

Answer 2

@tanner23456

Answer 3

@SolomonZelman

Answer 4

@mathstudent55

Answer 5

so slope or m = 3

I usually like to plot it on the graph and find where the line crosses the y-axis to find the y-intercept but you can also plug it into the point slope form

y - y1 = m(x-x1)

y - (-4) = 3(x-9)

it becomes

y + 4 = 3x - 27

subtract the 4

y = 3x - 31

C looks like the correct answer

Answer 6

I thought the answer was A but thank you for showing me how you worked that out.