Question

hayar x,y si x+6y=27 y 7x-3y=9

Answer 1

x + 6y = 27
7x - 3y = 9

despejamos
x = 27 - 6y
7x - 9 / 3 = y

método de sustitución
x = 27 - 6 (7x - 9 / 3)
x = 27 - 6 (7x - 3)
x = 27 - 42x + 13
x + 42x = 27 + 13
43x = 40
x = 40 / 43

y = 7 (40/43) - 9 / 3
y = 280/43 - 9 / 3
y = -107/43 / 3
y = -107/129