Respuesta :

y = -3x + 23

Equation of a line:

y = mx + c

Slope of -3:

m =  -3

y = -3x + c

Passes through the point (5,-8)

x = 5

y = 8

8 = -3(5) + c

8 = -15 + c

Solve to find c:

Add 15 to both sides.

8 + 15 = -15 + 15 + c

8 + 15 = c

23 = c

Equation

y = -3x + 23