kak tolong jawab no 5,6,7 ya kak pliss

5. AD=x
8/12=x/x+5
2/3=x/x+5
Dikali silang
2 kali x+5 = 3 kali x
2x+10 = 3x
X=10

7. PT=x
6/9= x/20-x
2/3=x/20-x
Kali silang
40-2x=3x
40=5x
X=8