Question

What is an equation of the line that passes through the points (-1, 3) and (-2,-1)?

Answer 1

Answer: y = 4x + 7

Explanation:

It's a line, so the formula is y = mx + b.

• (x₁, y₁) = (-1, 3)
• (x₂, y₂) = (-2, -1)

Slope(m):
`(y_(2) - y_(1))/(x_(2) - x_(1)) =(-1-3)/(-2-(-1)) =(-4)/(-1) =4`

Y-intercept(b):

`y=4x+b\\3=4(-1)+b\\3=-4+b\\b=3+4=7\\`

Therefore, y = mx + b = 4x + 7.