Answer:
I believe the answer is x=7
Explanation:
3x and 4x-1 are corresponding sides and so are 14 and 18.
You cross multiply with the smaller triangle lengths at the top.
3x/(4x-1)= 14/18
Cross multiply to get
18(3x)= 14(4x-1)
54x=56x-14
Subtract 54x on the other side and add 14 to the other (or subtract 56x to the other side)
you get 14=2x and divide 14 by 2 to get x=7