Sum of 54: X + Y = 54
Difference is 4: X - Y = 4
Solve for one variable first.
X = 4 + y (rewritten from second equation)
Now plug into the first equation for x
4 + y + y = 54
4 + 2y = 54 (subtract 4)
2y = 50 (divide by 2)
Y = 25
Now use Y to solve for X
X - 25 = 4 (add 25 on each side)
X = 29