Question 972554
1.) 5x^3-40 
First factor out the greatest common factor 5, the result is
{{{5(x^3-8)}}}
Use the pattern {{{a^3-b^3 = (a-b)(a^2+ab+b^2)}}}
The complete factored form is {{{highlight(5(x-2)(x^2+2x+4))}}}

2.) x^3+64 
Use the pattern {{{a^3+b^3 = (a+b)(a^2-ab+b^2)}}}
The factored form of {{{x^3+64}}} is {{{highlight((x+4)(x^2-4x+16))}}}

3.) x^2+36
 {{{x^2+36}}} is NOT factorable.