Answer:
the two numbers are 19 and 32
Explanation:
let's call the numbers x and y.
write out the equations
x + y = 51
x - y = 13
simplify the second equation
x = 13 + y
substitute into the first equation and simplify
(13 + y) + y = 51
13 + 2y = 51
2y = 51 - 13
2y = 38
y = 19
substitute y for 19 in the second equation
x = 13 + y
x = 13 + 19
x = 32