Question

Find2 numbers whose sum is 90 and their defferance is 12

Answer 1

let the now be X and y
X+y=90
x-y=12
2x=102
X==51
y=49

Answer 2

let first no. be x
second be y
a/q
x+y=90
x-y=12
using substitution method
90-y-y=12
90-2y=12
2y=78
y=39
so,
x=51