Question

Write an equation in slope intercept form of the line that passes through (4, 1) and (5, -1).
A. y = -4x + 1
B. y = -1/2 x + 9
C. y = 4x + 1
D. y = -2x + 9

Answer 1

@Nurali

Answer 2

1st... find slope
(-1-1) / (5-4) = -2/1 = -2

So the slope is -2.

Next step... find y-intercept. This is where the line crosses the y-axis.
To find it... use this equation
y=mx+b
m= slope = -2
b= y-intercept

Using slope and one of the coordinates you are given, find b
I'll use the (5, -1) one
y=mx+b
-1=-2(5)+b
b= 9

So slope is -2, b is 9. That's all you need!

Plug in those in the equation:
y=mx+b
y= -2x+9