Question

resolver os sistema 2*2 pelo metodo da substuição 5x+3y=22                                                                                                                  8x+5y=36                                                                           

Answer 1

(a) 8x+5y=36
(b)  5x+3y=22

De (b):

5x+3y=22
      3y=22-5x
        y=(22-5x)/3

Substituindo em (a):

$8x+5y=36 \\ \\ 8x+5.\frac{22-5x}{3} =36 \\ \\ 24x+110-25x=108 \\ \\ -x=-2 \\ \\ \boxed{x=2}$

Veja que :

$y=\frac{22-5x}{3} \\ \\ y=\frac{22-10}{3} \\ \\ \boxed{y=4}$

Answer 2

$\left \{ {{5x+3y=22} \atop {8x+5y=36}} \right.$

$5x+3y=22\\3y=22-5x\\ \\y= \frac{22-5x}{3}$

Substituindo na primeira.

$8x+5y=36\\ \\8x+5( \frac{22-5x}{3} )=36\\ \\8x+ \frac{110-25x}{3} =36\\ \\ \frac{24x+110-25x=108}{\not3} \\ \\24x+110-25x=108\\ \\-x=108-110\\-x=-2~\bullet(-1)\\ \\x=2$

Temos que :

$y= \frac{22-5x}{3} \\ \\y= \frac{22-5.2}{3} \\ \\y= \frac{22-10}{3} \\ \\y=4$