Let's say the two numbers are "a" and "b"
"a" being the smaller one, and "b" the larger one
so, their sum is 118, or a + b = 118
if 4 times the smallest, or 4*a or 4a
is subtracted from the largest, "b", so b - 4a
equals 18, so b - 4a = 18
thus
![\bf \begin{cases} a+b=118\implies \boxed{b}=118-a\\ b-4a=18\\ ----------\\ \left( \boxed{118-a} \right)-4a=18 \end{cases}](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Bcases%7D%0Aa%2Bb%3D118%5Cimplies%20%5Cboxed%7Bb%7D%3D118-a%5C%5C%0Ab-4a%3D18%5C%5C%0A----------%5C%5C%0A%5Cleft%28%20%5Cboxed%7B118-a%7D%20%5Cright%29-4a%3D18%0A%5Cend%7Bcases%7D)
solve for "a", to find the smaller one
what's b? well, b = 118 - a