Question

Find two consecutive number that have a product of 72?

Answer 1

let x and x+1 be two consecutive numbers .
A.T.Q,
x(x+1) = 72
x^2 + x = 72
x^2 + x - 72 = 0
x^2 +9x - 8x - 72 = 0
x( x+ 9 ) - 8 ( x+ 9 ) = 0
( x + 9 ) ( x-8 ) = 0
hence , x = -9 or 8
thus two no.s are either -9 ,-8 or 8 ,9

Answer 2

let the numbers be x and x+1

A T Q

x(x+1) = 72

x^2 + x - 72 = 0

x^2 +9x - 8x - 72 = 0

x( x + 9 ) (-)×8×(x + 9) =0

(x - 8)(x + 9) = 0

when x = 8
x + 1 = 9

when x = -9
x + 1 = -8