In this case, since one equation is in the form of x=, substitution would be best for this problem. Simply plug in 4y + 8 in place of x in the second equation, solve for y, then plug that value into the first equation to find x.
4926.25965251
I used a calculator because it makes solving this much easier
15/3 = 35/x
Cross multiply.
15x=105
105/15=x
x=7
Abe have to take 7 weeks of school this quarter.
