A.
5
B.
6
C.
9
D.
18
The train would at least be going 55 mph for that to happen.
Hey! Add me! :) Im 13 btw.
anyways, how you solve this problem is simple:
first:distribute, which 3(x+2) turns into 3x+6
then:set 3x+6 equal to x-18
subtract x from both sides, then add 18 to -18 and 6,
the result of this is 2x=24
divide 24 by 2, you get 12 so x is equal to 12.
Good LUCK! :) rate mine the best c: lyy