x=2
You first solve for y on the other equation 6x+3y=15 which will be: y=5-2x
Then you make it one equation: 3x-5=5-2x
Third step is add the -2x with the 3x which is will be 5x.
Fourth: your new equation will be 5x-5=5
Next u would add 5 plus which is 10
Lastly your new equation is 5x=10
I honestly hope this helps !!!!