A line passes through (1,-1) and (3,5). What is the equation of the line in slope-intercept form?

A.) Y = x-2

B.) Y = 3x-5

C.) Y = 3x-4

D.) Y = 2x-3

The best answer is C.) Y = 3x-4

(1,-1) and (3,5)

Find slope first

y=mx+b

slope is also m

b is y-intercept

slope = y2-y1/x2-x1

x1=1

x2=3

y1=-1

y2=5

5 - (-1) / (3) - (1)

6/2=3

y=3x+b

use (1,-1) into y=3x+b (using substitution method)

-1=3 (1) + b

-1=3+b

Move 3 to the other side

Sign changes from + 3 to - 3

-1-3+3-3+b

b=-4

Answer: C.) Y = 3x-4