Question

Answer 1

Câu 5.

\(4x^2+12x+9=0\\\Leftrightarrow (2x)^2+2\cdot2x\cdot3+3^2=0\\\Leftrightarrow (2x+3)^2=0\\\Leftrightarrow 2x+3=0\\\Leftrightarrow 2x=-3\\\Leftrightarrow x=\dfrac{-3}{2}\\\Rightarrow Chọn.B\)

Câu 7.

\(\dfrac{2+x}{3x^2y}+\dfrac{1-y}{3xy^2}\)

\(=\dfrac{y\left(2+x\right)}{3x^2y^2}+\dfrac{x\left(1-y\right)}{3x^2y^2}\)

\(=\dfrac{2y+xy+x-xy}{3x^2y^2}\)

\(=\dfrac{x+2y}{3x^2y^2}\)

Câu 8.

Bạn chụp lại đề nhé, đề hơi mờ.

\(Toru\)