Question 1024123
Hi there,
The sum of two numbers is 45. 
x + y = 45
their difference is 71
x - y = 71
........
x + y = 45
x - y = 71
add
2x   = 116
x    = 58
Substitute x = 58 into:-
x + y = 45
58 + y = 45
y = 45 - 58
y = -13
Two numbers are 58 and -13
Hope this helps :-)