Question

x^2+7x+10=0 tim x

Answer 1

Ta có:

x² + 7x + 10 = 0

<=> x^2 + 5x + 2x + 10 = 0

<=> x(x + 5) + 2(x + 5) = 0

<=> (x+2)(x+5) = 0

<=> x+2=0 hoặc x+5=0

<=> x= -2 hoặc x= -5

Vậy x = -2; -5.

Answer 2

\(x^2+7x+10=0\)

\(\Leftrightarrow\left(x^2+5x\right)+\left(2x+10\right)=0\)

\(\Leftrightarrow x\left(x+5\right)+2\left(x+5\right)=0\)

\(\Leftrightarrow\left(x+5\right)\left(x+2\right)=0\)

\(\Leftrightarrow\hept{\begin{cases}x+5=0\\x+2=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=-5\\x=-2\end{cases}}}\)