Answer:
7 weeks
Step-by-step explanation:
John saves f(x) = 60+5x
Sarah saves g(x) =x^2 +46
They save the same amount of money
Set the equations equal
60+5x =x^2 +46
Subtract 60 from each side
60+5x -60 =x^2 +46-60
5x= x^2 - 14
Subtract 5x from each side
5x -5x= x^2-5x - 14
0 = x^2-5x - 14
Factor
0 = (x-7) (x+2)
Using the zero product property
x-7=0 x+2 =0
x=7 x=-2
Since we cannot have negative weeks
x=7
