What is the value of y in the following system y = 3x-5 6x+3y=15

X=2. You use substitution to put the y=3x-5 into 6x+3y=15.

So you get 6x+3 (3x-5) = 15

=6x+9x-15=15

add 15 on both sides to get the x's alone and add the x's together.

6+9=15 - - 15+15=30

15x=30

30/15 = 2

x=2

If you plug in (3x-5) in for y in the 6x+3y=15, you will get 6x+9x-15=15. Add the like terms (6x+9x) and get 15x. Bring the - 15=15 down. Add 15 to the other 15 on the other side of the equal sign, bring 15x down and then divide 15 by 30 and get x=2. Plug in 2 for x in the (3x-5) equation, then solve and the answer will be 1.