Question

Rút gọn biểu thức B=(4a^2+12a+9)/(2a^2-a-6)

Answer 1

Rút gọn biểu thức B=\(\dfrac{4a^2+12a+9}{2a^2-a-6}=\dfrac{\left(2a+3\right)^2}{2a^2-4a+3a-6}=\dfrac{\left(2a+3\right)^2}{2a\left(a-2\right)+3\left(a-2\right)}=\dfrac{\left(2a+3\right)^2}{\left(a-2\right)\left(2a+3\right)}=\dfrac{2a+3}{a-2}\)

Answer 2

B\(=\dfrac{4a^2+12a+9}{2a^2-a-6}\)

⇒B\(=\dfrac{\left(2a+3\right)^2}{2a^2-4a+3a-6}\)

⇒B\(=\dfrac{\left(2a+3\right)^2}{2a\left(a-2\right)+3\left(a-2\right)}\)

⇒B\(=\dfrac{\left(2a+3\right)^2}{\left(a-2\right)\left(2a+3\right)}\)

⇒B\(=\dfrac{2a+3}{a-2}\)