The sum of two numbers is 84. Their difference is 32

Set it up like:

x + y = 84

x - y = 32

You can add the equations to eliminate y:

2x + 0y = 116

2x = 116; now divide by 2 to isolate the x, and you get x = 58

Now plug x = 58 into either equation and solve for y.

58 + y = 84; subtract 58 from both sides to isolate y, and you get y = 26