There are many ways to solve this!
Simplify:
(look at this as a fraction, lol)
c2+x+100
5
Divide:
c2/55 + x/55 + 20/11 (nothing further can be done)
Solve for x:
(43 + c2 + 57 + x) ÷ 55 (again, nothing further can be done)
Hope I helped a little!