Answer:x=6
Step-by-step explanation:
YZ is 1/2 of EF, so the same goes for the other sides. ED is 10, so XY is 5, 5=x-1, solve for x, and you get x=6. And to verify, XY is 7.5, so DF would be double that, so 15=3(x-1), which is correct 15=3(6-1)=3(5)
