Answer:
A
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Here m = - 3 , thus
y = - 3x + c ← is the partial equation
To find c substitute (7, 8) into the partial equation
8 = - 21 + c ⇒ c = 8 + 21 = 29
y = - 3x + 29 → A