Question

if
$n - m = - 3$

and
$m + n = 5$

find the value of m and n

Answer 1

n-m=-3
n+m=5
...............
2n=2
n=2/2
n=1
n+m=5
1+m=5
m=5-1
m=4
m=4,n=1 is answer