Question

9) Na equação (m – 2) . x + 2x + 4(m – 5) = 0, temos que x=2. Qual o valor de m?

Answer 1

Basta substituir o "x" na equação pelo valor fornecido (2).

$(m-2)\cdot x~+~2x~+~4\cdot(m-5)~=~0\\\\\\(m-2)\cdot 2~+~2\cdot2~+~4\cdot(m-5)~=~0\\\\\\2\cdot m~-~2\cdot2~+~4~+~4\cdot m~-~4\cdot5~=~0\\\\\\2m~-~4~+~4~+~4m~-~20~=~0\\\\\\2m~+~4m~=~4-4+20\\\\\\6m~=~20\\\\\\m~=~\dfrac{20}{6}\\\\\\\boxed{m~=~\dfrac{10}{3}}$