Question

the greater of two numbers is 12 an the sum of the two numbers is 10 .find the number​

Answer 1

Let x n y be the number 
X be greater than Y.
ATP:
X=12+y.......1

X+y=10.......2
Substitute 1 in 2 
(12+y)+y=10
12+2y=10
2y=-2
Y=-1

X=12+(-1)
=11

Answer 2

Let the other number be x

12 + x = 10

x = 10 - 12

x = - 2

Therefore, the other number = - 2

Hope this helps you :)