Question

What is the equation of the line through (-2, 5) and (0, 3)? A. y = x - 3 B. y=x+3 C. y = -x + 3 D. y=-x-3​

Answer 1

C

Explanation:

a typical line equation is the slope-intercept form

y = ax + b

"a" is the slope (always the factor of x) expressed as ratio of "y coordinate difference" / "x coordinate difference".

b is the y-intercept (the y value when x = 0).

going from (-2, 5) to (0, 3) we see

x changes by +2 (from -2 to 0).

y changes by -2 (from 5 to 3).

so the slope is -2/+2 = -1

using one of the points (0, 3) to solve for the missing b :

3 = -1×0 + b

b = 3

so, the equation is

y = -x + 3