Question

(X+2)(X+3)(X+4)=990

I know that x=7 but how do i solve it without substitution?

ie. i don't want to use y=x+3 where 990=(y-1)(y)(y+1)

Answer 1

Explanation:

foctorized 990 = 9×10×11

so, (X+2)(X+3)(X+4)=9×10×11

we can choose one of the factors, and get the answer with the same x values

x+2 = 9 , => x =7

x+3 = 10, => x = 7

x+4 = 11, => x = 7