Answer:
C
Step-by-step explanation:
The first one (0,7) tells you that when x isn't there, the amount of money is 7.
That means that the y intercept is 7.
When x = 1 the total is 15
Money saved = ax + 7
15 = a*1 + 7 Subtract 7
15-7 = a + 7-7
a = 8
The equation is f(x) = 8x + 7
