Question

Resolva a equação dada por: $\left[\begin{array}{ccc}2x&-2\\-3&x&\end{array}\right]$ = $\left[\begin{array}{ccc}x&x²&0\\1&2&3\\2&3&5\end{array}\right]$

Answer 1

Ao fazer:

$det\left[\begin{array}{cc}2x&-2\\-3&x\end{array}\right] = det \left[\begin{array}{ccc}x&x^2&0\\1&2&3\\2&3&5\end{array}\right] \\2x^2 - 6 = 10x + 6x^2 + 9x + 5x^2\\9x^2 +19x + 6 =0$

9x² +19x + 6 =0

Δ= 19² - 4.9.6

Δ = 361 - 216

Δ = 145   =====> Arredonda para 144  XD

x₁ = $\frac{-19 + 12}{2.9} = \frac{-6}{18} = -\frac{1}{3}$

x₂ = $\frac{-19 - 12}{2.9} = -\frac{31}{18}$