Question

The sum of number is 16 and the sum of their square is 130.Find the number​

Answer 1

let y=other number
..
x-y=16
x^2+y^2=130
..
x=y+16
(y+16)^2+y^2=130
y^2+32y+256+y^2=130
2y^2+32y+126=0
y^2+16y+63=0
(y+7)(y+9)=0
y=-7
x=y+16=9
or
y=-9
x=y+16=7
..
The two pairs of numbers are: (9 and-7) and (7 and-9)