Find the sum of two numbers is 2, and their difference is 26. Find the numbers

x + y = 2

x - y = 26

Add the two equations:
2x = 28

x = 14

Subtract the second original equation from the first one:
2y = -24

y = -12

Sum: 14 - 12 = 2
Difference: 14 - (-12) = 26