Question

gente alguém me ajuda Pf???

Answer 1

7 x + 6y = 23

5 x + 6x = 21  --->  11x = 21 // x = 21/11

_________________________________________________________

7 x + 6y = 23 // 7(21/11) + 6y = 23 // 147/11 + 6y = 23 // 6y = 23 - 147/11 //

y = 23/6 - 147/66

mmc (6;66) = 66

y = [23+66/6]/66 - 147/66

y = 23+11 /66 - 147/66

y = 34/66 - 147/66

y = - 113/66