Question 872881
(x + 1)(x + 3)(x + 5)(x + 7) = 9

(x+1)(x+7)(x+3)(x+5)=9

(x^2+8x+7)(x^2+8x+15)=9

let x^2+8x=a

(a+7)(a+15)=9

a^2+22a+105=9

a^2+22a+96=0

a^2-16x-6x+96=0

a(a-16)-6(a-16)=0

(a-16)(a-6)=0

(x^2+8x-16)(x^2+8x-6)=0
each factor can be zero

solve both the factors by formula method you will get four vaues for x