Question

x+y=37
5x+7y=52
ajudem pfv

Answer 1

Resposta:

Explicação passo a passo:

$\left\{\begin{array}{ccc}x+y=37\\\\5x+7y=52\end{array}\right$

$Multiplicamos\:a\:equacao\:de\:cima\:por\:-5$

$\left\{\begin{array}{ccc}-5x-5y=-185\\\\5x+7y=52\end{array}\right$

$Vamos\:somar\:as\:duas\:equacoes...$

 $2y=-133$

   $y=-\frac{133}{2}$

   $y=-66,5$

  $x+y=37$

  $x=37-y$

 $x=37-(-66,5)$

 $x=37+66,5$

 $x=103,5$

$S=\{(x;y)\}=\{(103,5\:;-66,5)\}$

 

Answer 2

Resposta:

x = 207/2

Y = - 133/2

Explicação passo a passo:

X+y=37 (-5)

5x+7y=52

- 5x - 5y = - 185

5x + 7y = 52 (+)

-------------------

2y = - 133

y = - 133/2

x + y = 37

x - 133/2 = 37

x = 37 + 133/2

x = (2.37+133)/2

x = (74 + 133)/2

x = 207/2

R.:

x = 207/2

Y = - 133/2