Step 1) Write two equations
x - smaller number
y - larger number
x + y = 63
x + 7y = 261
Step two use elimination method to solve for one of the variables.
(-1) (x + y = 63) -> -x - y = -63
x + 7y = 261
-----------------
6y = 198
--- ----
6 6
y = 33
Step 3: Substitute the solution into one of the original two equations
x + y = 63
x + 33 = 63
- 33 = -33
------------------
x = 30
x = 30
y = 33