Question

-x(2x+1)-2(x²+x+5)=7

Answer 1

\(\Leftrightarrow-2x^2-x-2x^2-2x-10=7\)

\(\Leftrightarrow-4x^2-3x-17=0\)

\(\Leftrightarrow4x^2+3x+17=0\)

\(\text{Δ}=3^2-4\cdot4\cdot17< 0\)

Do đó: PT VN

Answer 2

<=> \(-2x^2-x-2x^2-2x-10-7=0\)

<=> \(-4x^2-3x-17=0\)

-> PT vô nghiệm