Answer:
y = - x + 11
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 = - , then
y = - x + c ← is the partial equation
To find c substitute (8, - 9) into the partial equation
- 9 = - 20 + c ⇒ c = - 9 + 20 = 11
y = - x + 11 ← equation of line
$128.49
4 gallons at $15.72 each is 4×$15.72 = $62.88
3 gallons at $21.87 each is 3×$21.87 = $65.61
The total purchase is ...
$62.88 +65.61 = $128.49
Tim will be spending $128.49 on paint.
Opps, wrong answer
Deleted