i cant seem to get the answer that the teacher gave us which is 5y^2-11y

The problem is simplify:
2y^2-y[3-2(y-4)-y]

how did he get that answer?

3 answers

2y^2-y(3-2(y-4)-y)

Get rid of the inner brackets:

2y^2 - y(3 - 2y + 8 -y)

Multiply the y into the brackets:

2y^2 - (3y - 2y^2 + 8y - y^2)

2y^2 - 3y + 2y^2 - 8y + y^2

Now collect the terms together.
Thanks
You're welcome!