Question

x^2(-x^2-100)<=100(-x^2-100)

Answer 1

$x^2(-x^2-100) \leq 100(-x^2-100) \\ x^2(-x^2-100)-100(-x^2-100) \leq 0 \\ (-x^2-100)(x^2-100) \leq 0 \\ -(x^2+100)(x^2-100) \leq 0 \\ -(x^4-10000) \leq 0 \\ -x^4+10000 \leq 0 \\ -x^4 \leq -10000 \\x \leq \sqrt[4]{10000} \\ x \leq 10$