Answer:
x = 2
Step-by-step explanation:
If B and D are midpoints, then you have to similar triangles ACE and BCD that have a constant ratio on their corresponding sides.
That ratio is 1:2 for any side of triangle BCD compared to corresponding side on triangle ACE,
Then BD / AE = 1/2
cross multiplying:
2 * BD = AE
replacing with their expression in terms of x:
2 (5 x + 3) = 4 x + 18
using distributive property:
10 x + 6 = 4 x + 18
solving for x:
10 x - 4 x = 18 - 6
6 x = 12
x = 2
