We have
[tex]3y+8-7y=11[/tex]
First, we can combine like terms 3y and -7y to get -4y.
Then, we have[tex]-4y+8=11[/tex] We could then subtract 8 on both sides to get [tex]-4y=3[/tex]
Finally, we isolate y completely by dividing both sides by -4, to get
[tex]y=- \frac{3}{4} [/tex]