Question

What is the value of x in the equation −6 + x = −3? −9 −3 3 9?

Answer 1

$a^6+x=a^3\ \ \ |-a^6\\\\\boxed{x=a^3-a^6}\to x=a^3(1-a^3)\\\\x=a^3(1^3-a^3)\to x=a^3\underbrace{(1-a)(1+a+a^2)}_{a^3-b^3=(a-b)(a^2+ab+b^2)}$