Need help with this question 88 points

Lets draw a picture:

We can see that triangle ABC and triangle BCD are similar. Then the following ration must be preserve:

Which gives:

If we move 18 to the right hand side, we get

Which gives:

Then, x is equal to 14.4 units.

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^

i think it would be 42cm