Question

6x+3y=8x+9y-5=10x+12y-8 solve by elimination method

Answer 1

6x+3y=8x+9y-5              1)  5=2x+6y
2) 10x+12y-8

multiply 1)by 5
3) 10x+30y=25

Subtracting 3) and 2)
10x+30y=25
10x+12y=8
-     -        -
18y=17
y=17/18

Substitiuting the value of y in 1)

5=2x+6(17/18)
5=2x+17/3
2x=5-17/3
2x=15-17/3
x=15-17/6
x=-1/3

Answer 2

You have done correct but at last step I.e

2x=5-17/3

2x=15-17/3

2x=-3/3

2x=-1

x=-1/2