-4x^2+13x+12>=0 Срочно плиз

Question

-4x^2+13x+12>=0
Срочно плиз

Answer 1

4x²-13x-12≤0
D=13²+4*4*12=169+192=361=19²
x₁=(13-19)/8=-6/8=-3/4=-0.75
x₂=(13+19)/8=4

4(x+0.75)(x-4)≤0
x∈[-0.75; 4]