Question

1 ) resolva o sistema. 

7x - 2y = 31
5x + 6y = - 15
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Answer 1

Oi...

7x - 2y = 31

5x + 6y = - 15

6y = - 5x - 15

y = - 5x/6 - 5/2

7x -2(-5x/6 - 5/2) = 31

26x/3 = 26

26x = 78

x = 78/26

x = 3

y = - 5x/6 - 5/2

y= -(5/6)(3) - 5/2

y = -5/2 - 5/2

y = - 5 - 5/2

y = - 10/2

y = - 5

S = {x = 3 e y = - 5}

Espero ter ajudado