(x^2-9)(x^3-8)=0
as you can see that (x^2-9) is in the form of a^2 - b^2 which equals (a+b)(a-b)
x^2 - 9
= (x)^2 -(3)^2
= (x+3)(x-3)
now, the equation becomes
(x+3)(x-3)(x^3-8)=0
(x+3) =0
x = -3
(x-3) = 0
x = 3
x^3 -8 = 0
x^3 = 8
x = cube rt. 8
= 2
so, the three solutions are -3, 3 and 2.
