Question

Two numbers differ by 4 and their product is 96. Find the numbers.

Answer 1

Let the numbers be x and y. x-y= 4 and xy= 96 which implies that y is 96/x. Substituting y in first equation x- (96/x) = 4 you get x square - 4x -96 = 0 which means that the root values are -12 and 8. X can't be negative so we consider the positive value which is 8. Substituting 8 in y= 96/x you get y as 12. The numbers are 12 and 8.

Answer 2

let the nos be x and y
x-y=4.....(i)
xy=96
y=96/x
putting this in (i)
x-96/x=4
⇒x²-4x-96=0
⇒(x-12)(x+8)=0
⇒x=12 or x=-8
so y=8 or y=-12