Question

Решите неравенство: x^2+7x-18<или равно 0

Answer 1

x2+7x-18≤0
x2+7x-18=0
D=7^2-4×1×(-18)=49+72=121
x1=-7+11/2×1=4/2≤2
x2=-7-11/2×1=-18/2≤-9
[-9;2]