Question

1.Analize e descubra o resultado desse sistema de equação.

{3x+2y=-5
{x-2y=-7

2.Considere o sistema {5x-3y=15
{2x+3y=6
encontre o resultado de x e y.

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Answer 1

$\boxed{\begin{array}{l}\rm 1)~ Analise~e~descubra~o~resultado~desse~sistema~de~equac_{\!\!,}\tilde oes\\\begin{cases}\sf 3x+2y=-5\\\sf x-2y=-7\end{cases}\end{array}}$

$\boxed{\begin{array}{l}\underline{\sf soluc_{\!\!,}\tilde ao\!:} \\\tt a) ~\begin{cases}\sf 3x+2y=-5\\\sf x-2y=-7\end{cases}\\\underline{\rm somando~algebricamente~as~ equac_{\!\!,}\tilde oes~temos}\\+\underline{\begin{cases}\sf 3x+\backslash\!\! \!2y=-5\\\sf x-\backslash\!\!\!2y=-7\end{cases}}\\\sf4x=-12\\\sf x=-\dfrac{12}{4}\\\sf x =-3\\\sf x-2y=-7\\\sf -3-2y=-7\\\sf 2y=7-3\\\sf 2y=4\\\sf y=\dfrac{4}{2}\\\sf y=2\\\sf S=\{(-3,2)\}\end{array}}$

$\boxed{\begin{array}{l}\rm 2)~ Considere ~o~sistema~\begin{cases}\sf5x-3y=15\\\sf 2x+3y=6\end{cases}. \\\rm encontre~o~resultado~de~x~e~y.\end{array}}$

$\boxed{\begin{array}{l}\underline{\sf soluc_{\!\!,}\tilde ao\!:}\\\begin{cases}\sf5x-3y=15\\\sf2x+3y=6\end{cases}\\\underline{\rm somando~as~equac_{\!\!,}\tilde oes~membro~a~membro~temos\!:}\\+\underline{\begin{cases}\sf5x-\backslash\!\!\!3y\\\sf2x+\backslash\!\!\!3y\end{cases}}\\\sf7x=21\\\sf x=\dfrac{21}{7}\\\sf x=3\\\sf 2x+3y=6\\\sf2\cdot3+3y=6\\\sf 6+3y=6\\\sf 3y=6-6\\\sf 3y=0\\\sf y=\dfrac{0}{3}\\\sf y=0\\\sf S=\{(3,0)\}\end{array}}$

Answer 2

Resposta:

{3x+2y=-5

{x-2y=-7

4x=-12

x=-12/4

x=-3

3x+2y=-5

3•(-3)+2y=-5

-9+2y=-5

-9+9+2y=-5+y

2y=4

y=4/2

y=2

s=(-3,2)

{5x-3y=15

{2x+3y=6

7x=21

x=21/7

x=3

2x+3y=6

3•3+3y=6

6-6+3y=6-6

3y=0

y=0/3

y0

s=(3,0)