Question

Resolva as equações abaixo:

a) b) [5x] = -1

b) [ 2x - 1 x+5]
[ 4 -5] = 13

c) [ 3 1 -1]
[-1 0 x] = -3
[-6 2 5]

Answer 1

Explicação passo-a-passo:

a)

$\sf \Big| \begin{array}{c} \sf 5x \end{array}\Big|=-1$

$\sf 5x=-1$

$\sf \red{x=\dfrac{-1}{5}}$

b)

$\sf \Big| \begin{array}{cc} \sf 2x-1 & \sf x+5 \\ \sf 4 & \sf -5 \end{array}\Big|=13$

$\sf -5\cdot(2x-1)-4\cdot(x+5)=13$

$\sf -10x+5-4x-20=13$

$\sf -14x-15=13~~~\cdot(-1)$

$\sf 14x+15=-13$

$\sf 14x=-13-15$

$\sf 14x=-28$

$\sf x=\dfrac{-28}{14}$

$\sf \red{x=-2}$

c)

$\sf \Big| \begin{array}{ccc} \sf 3 & \sf 1 & \sf -1 \\ \sf -1 & \sf 0 & \sf x \\ \sf -6 & \sf 2 & \sf 5 \end{array}\Big|=-3$

$\sf 3\cdot0\cdot5+1\cdot x\cdot(-6)+(-1)\cdot(-1)\cdot2-(-6)\cdot0\cdot(-1)-2\cdot x\cdot3-5\cdot(-1)\cdot1=-3$

$\sf 0-6x+2-0-6x+5=-3$

$\sf -12x+7=-3~~~\cdot(-1)$

$\sf 12x-7=3$

$\sf 12x=3+7$

$\sf 12x=10$

$\sf x=\dfrac{10}{12}$

$\sf \red{x=\dfrac{5}{6}}$

Answer 2

a) b) [5x] = -1

$=$

$b = - \frac{1}{5x}$

b) [ 2x - 1 x+5]

[ 4 -5] = 13

$=$

$x = - 18$

c) [ 3 1 -1]

[-1 0 x] = -3

[-6 2 5]

$=$

$x = - \frac{25}{4}$

Здрастуйте

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