Answer:
y = - x + 13
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 = - 1, thus
y = - x + c ← is the partial equation
To find c substitute (9, 4) into the partial equation
4 = - 9 + c ⇒ c = 4 + 9 = 13
y = - x + 13 ← equation in slope- intercept form
