Answer:
ABC is a 90 degree angle and CBD is a 30 degree.
Step-by-step explanation:
If u look at ABC you can see that its a right angle and CBD is 30 degrees because its the exact same angle as EBF!!!
to simplify it, we need to combine like terms. 8 and 15 are like, and 5x and 2x are like. so we rearrange it: 8+15-5x-2x
and now we simplify: 23-7x
5.5 cm
(Rounded up)