Which equation represents the line that passes through the points (3,7)(3,7) and (-1,-1)(-1,-1) ?

Question

y=2x+1y=2x+1

y=−2x+13y=-2x+13

y=3x−2y=3x-2

y=−3x+16

these are my choice

Answer 1

First, find the slope:

m = (y₂ - y₁) / (x₂ - x₁)

m = (-1 - 7) / (-1 - 3)

(-8) / (-4)

m = 8/4

m = 2

 

Now we use the point-slope formula:

y - y₁ = m(x - x₁)

It doesn't matter which coordinate we use, so I'll use (-1, -1):

y - (-1) = 2(x - (-1))

y + 1 = 2(x + 1)

y + 1 - 2x + 2

y = 2x + 1