Question

2x - y = 9
3z - y = 12
x + y + z = 14

ache a incógnita

Answer 1

2x - y= 9
2x = 9 + y
x = (9+y) / 2

3z - y = 12
3z = 12 + y
z = (12+y) / 3

x + y + z = 14
(9+y)/2 + y + (12+y)/3 = 14
3(9+y) / 6 + 6y/6 + 2(12+y)/6 = 14
(27 + 3y + 6y + 24 + 2y) / 6 = 14
11y +51 = 14 . 6
11y = 84 - 51
11y = 33
y = 33/11
y = 3

x= (9+y)/2 = (9+3)/2 = 12/2 = 6
z= (12+y)/3 = (12+3)/3 = 15/3 = 5