Question

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os determinantes nas equações abaixo:
 

Answer 1

Olá, Flavinho.

$a)\ x(3x+2)-2(x+2)\Rightarrow 3x^2+2x-2x-4=\boxed{2x^2-4}\\\\ b)\ 0\cdot2\cdot(-1)+3\cdot4\cdot1+2\cdot1\cdot x-2\cdot2\cdot1-4\cdot1\cdot0-(-1)\cdot x\cdot3=\\\\=0+12+2x-4-0+3x=5x+8\Rightarrow\\\\ 5x+8=6\Rightarrow 5x=-2\Rightarrow \boxed{x=-\frac25}$