Tolong no.10-12 please urgent.

no. 10
TU:PR=TQ:PQ
4:6=(x+3):(4+(x+3))
2:3=(x+3):(x+7)
2(x+7)=3(x+3)
2x+14=3x+9
14-9=3x-2x
5=x
JADI, x = 5

no. 11
CB = x
CD = x+4

BA:DE=CB:CD
6:9=x:(x+4)
6(x+4)=9x
2(x+4)=3x
2x+8=3x
8=3x-2x
8=x

CD=x+4=8+4=12

no. 12
4:OC=8:10
4:OC=4:5

OC=5