5. x=15
6. x=20
7. x=15
8. x=10 y=8.8
9. x=12 y=15.4
10. x=10 y=9
im not ~too~ sure about #9 but im pretty sure thats right. anyway you just divide pretty much. for example on #1 30 divided by 20 is 1.5 so you just multiply 10 times 1.5 to get 15 which is its similar side.