Question

1 ) resolva o sistema.

$7x - 2y = 31 \\ 5x + 6y = - 15$
me ajudem !​

Answer 1

Resposta:

7x - 2y = 31   ×3          = 21x - 6y = 93    

5x + 6y = 15                 = 5x + 6y = 15

 21x - 6y = 93  

+ 5x + 6y = 15

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

26x = 108

x = 108/26 :2

x = 52/13

substituindo valor de x

7(52/13) - 2y = 31

(364/13) -2y = 31

364 - 26y = 403

- 26y = 403 - 364

- 26y = 39    ×(-1)

26y = - 39

y = - 39/26