Question

Determinante (Matriz)

║x x+2 ║   
║5 7     ║    = 0

como faz x+2 * 5?

Answer 1

Ae,

aplique o mesmo procedimento usado para determinante de 2a ordem:

  $\left|\begin{array}{ccc}\text{x}&\text{x+2}\\5&7\\\end{array}\right|=0\\\\\\7\cdot\text{x}-5\cdot(\text{x}+2)=0\\7\text{x}-5\text{x}-10=0\\2\text{x}=10\\\\\text{x}= \dfrac{10}{2}\\\\\text{x}=5\\\\\\\Large\boxed{\text{S}=\{5\}}$

Tenha ótimos estudos ;P