Find EM.
Can anyone help me with this?

The little red dashes on the segments means they are congruent. EM = MG
Let's plug the expressions from the picture into our equation above.
7x = 8x - 6
Subtract 8x from both sides.
-x = -6
Divide both sides by -1
x = 6
EM = 7x = 7(6) = 42