Question

resolva as equações incompletas.
a) 2ײ = 8×
b) 7ײ+ 14×= 0

Answer 1

a) $2x^{2}=8x$

$2x^{2}-8x=0\\ \\ 2x\cdot \left(x-4 \right )=0\\ \\ \begin{array}{rcl} 2x=0&\text{ ou }&x-4=0 \end{array}\\ \\ \boxed{\begin{array}{rcl} x=0&\text{ ou }&x=4 \end{array}}$


b) $7x^{2}+14x=0$

$7x\cdot \left(x+2 \right )=0\\ \\ \begin{array}{rcl} 7x=0&\text{ ou }&x+2=0 \end{array}\\ \\ \boxed{\begin{array}{rcl} x=0&\text{ ou }&x=-2 \end{array}}$