5=1/2x+3y 10-x=6y

Answer 1

Multiply the 1st equation by 2. In the 1st equation, keep 6y alone on the right hand side of the equals sign. You will see that the 1st and 2nd equations are the same. Solution is 0=0, no solution!

Answer 2

If you multiply the first equation by -2 then add it to the second everything cancels out and you get 0=0

so no solution