The answer is C.
The arc length is 6.806784.
Hope this helps.
The equation has no solution because:
5(n+10)=5n+10n
5n+10n=5n+10n
I subtract 5n from both sides
10n=10n
Only one side is supposed to have the variable which is n, so the equation has no solution.
First, find out how much stan gets per week.
.25 x 7 =1.75
now how much they get together
1.75 + 1.20 = 2.95
and then the final step
23.60 / 2.95 = 8
it'll take 8 weeks for them to buy the model car set