Question

Quanto é: (x+6)(3-x)=20​

Answer 1

Resposta:

(x+6).(3-x)=20

3x-x²+18-6x=20

-x²-3x+18-20=0

-x²-3x-2=0

x²+3x+2=0

Δ=9-8

Δ=1

x=-3±√1/2

x'=-3+1/2=-2/2=-1

x"=-3-1/2=-4/2=-2

S={-1,-2}

Explicação passo-a-passo: