Question

resolver utilizando o método da fatoracao as raízes da equação: x²-10x + 21=0​

Answer 1

$\Large\mathsf\displaystyle{} {x}^{2} - 10x + 21 = 0 \\ \Large\mathsf\displaystyle{} {x}^{2} - 3x - 7x + 21 = 0 \\ \Large\mathsf\displaystyle{}x\cdot\left(x - 3\right) - 7\left(x - 3\right) = 0 \\ \Large\mathsf\displaystyle{}\left(x - 3\right)\cdot\left(x - 7\right) = 0 \\ \Large\mathsf\displaystyle{}x - 3 = 0 \\\Large\mathsf\displaystyle{}x - 7 = 0 \\\\\Large\mathsf\displaystyle{}x = 3 \\\Large\mathsf\displaystyle{}x = 7$

Solução:

$\Large\displaystyle\text{ \begin{gathered} \underline{\boxed{\boldsymbol{ x_{1} = 3 }}}\end{gathered} }$

$\Large\displaystyle\text{ \begin{gathered} \underline{\boxed{\boldsymbol{ x_{2} = 7 }}}\end{gathered} }$