Question

12x=54-6y,-17x=-62-6y

Answer 1

12x + 6y = 54
17x - 6y = 62
Sub two equ
29x = 116
x = 4
12*4 + 6y = 54
6y = 54 - 48
6y = 6
y = 1

Answer 2

12x = 54 - 6y.....multiply by -1
-17x = -62 - 6y
-----------------
-12x = -54 + 6y (result of multiplying by -1)
-17x = -62 - 6y
-----------------add
-29x = - 116
x = -116/-29
x = 4

12(4) = 54 - 6y
48 = 54 - 6y
48 - 54 = -6y
-6 = -6y
-6/-6 = y
1 = y

solution is (4,1)