ANSWER
10 weeks, $310
EXPLANATION
We have a system of linear equations as both equations need to be satisfied by the same ordered pair (x,y):
y = 25x + 60
y = 30x + 10
We can solve this by substitution. Since y is equal to 25x+60, we can substitute in 25x + 60 for y in the equation y=30x+10
y = 30x + 10
25x + 60 = 30x + 10
Subtract 25x from both sides
60 = 5x + 10
Subtract 10 from both sides and then divide both sides by 5
50 = 5x
x = 10
x represents time in weeks, so 10 weeks.
Find y, the amount of money, by substituting x=10 into either equation.
If we use y = 30x + 10, then
y = 30x + 10
y = 30(10) + 10
y = 300 + 10
y = 310
y = 310 implies $310 so the answer is 10 weeks, $310.
