Question

The sum of two numbers is 55 and the difference is 9. what are the numbers?

Answer 1

X + y= 55
x - y= 9
y = 23
x = 32

the numbers are 23 and 32

Answer 2

Difference is 9: x-y=9
From the second equation x=9+y (substitute that into the first equation to solve for y).
9+y+y=55


2y=46

y=23. (Substitute that back into the second equation to find x.)
x=9+y = 23+9 = 32.
23+32 = 55 (Check).