Sum is addition: X +Y = 51
Difference is subtraction: x -y = 25
Rewrite the second equation as x-25 = y
Replace y in the first equation with x-25:
x + x-25 = 51
Simplify:
2x -25 = 51
Add 25 to each side:
2x = 76
Divide both sides by 2:
X = 76/2
X = 38
Replace x in the first equation and solve for y:
38 + y = 51
y = 51-38
y = 13
So 38 + 13 = 561 and 38 -13 = 25
Large number = 38
Small number = 13