Question

Решите неравенство 4х² + 10х - 20≤ (х+2)²

Answer 1

4х² + 10х - 20≤ (х+2)²
4х² + 10х - 20≤ x²+4x+4
4х² -x² + 10х - 4x- 20-4 ≤0
3x²+6x-24≤0
x²+2x-8≤0

x²+2x-8=0
x₁+x₂= -2
x₁x₂= -8
x₁= -4
x₂=2

______+______-4________-______2______+_____

xє[-4; 2]