Answer:
-3
Step-by-step explanation:
y = -3x + b
-7 = -3(-3) + b
-7 = 9 + b
-16 = b
y = -3x - 16
You would divide negative 3 (-3) from both sides to keep the c by itself. When you divide a positive by a negative it becomes negative.
Dividing 15 by -3 would equal -5, so c = -5
7 x 10 = 70$
She earned 70$
