How to find y-intercept?

Question

I have the point (0,1) and (2,-3) and when I try I keep getting 1.5 but the book says the answers 1

Answer 1

The points are (0, 1) and (2, -3).

Substitute (x₁, y₁) = (0, 1) and (x₂, y₂) = (2, -3) in the two points form of line equation: y - y₁ = [(y₂ - y₁)/(x₂ - x₁)](x - x₁).

y - 1 = [(-3 - 1)/(2 - 0)](x - 0)

y - 1 = -2x

y = -2x + 1

Compare the above equation with slope-intercept form of line equation, y = mx + b, where m = slope and b = y-intercept.

Therefore, y-intercept is 1.