Nomor 6,7,8. Tolong bantu yah.

no.6
6/9 = 10/10+x
2/3 = 10/10+x
20+2x = 30
2x = 30-20
2x = 10
x = 5

no. 7
PS kuadrat = RS x SQ
PS kuadrat = 9 (13-9)
PS kuadrat = 9 x 4 = 36
PS = √36 = 6

no. 8
(3 x 18) + (5 x 6)/3+5
=54+30/8
=84/8
=10,5

*semoga membantu. sukses selalu ^_^