You can put this solution on YOUR website! 2y+7+4=y
==> 2y + 11 = y
adding -y to both the sides,
2y + 11 - y = 0
adding -11 to both the sides.
y + 11 -11 = -11
=> y = -11
Check:
2y+7+4=y
Replacing y by -11,
2(-11) + 11 = -11
==> -22 + 11 = -11
==> -11 = -11
Hence the solution of y = -11 is correct.