Bantu yah guys no 7-9 pake cara :) #Need quick answer JANGAN ASAL JAWAB !

7)[80.000×(100%-20%)×3]+[45.000×(100%-20%)×2]=(80.000×80%×3)+(45.000×80%×2)
=192.000+72.000=264.000 (B)
8)
modal awal (M○) = 5.000.000
persentase (p%) = 15% pertahun
waktu (t) = 5 bulan = 5/12 tahun
bunga = ....?
jawab :
bunga = M○ × p% × t
= 5.000.000 × 15% × 5/12
= 312.500 (D)
9)
suku ke 3 = 8 = a + 2b
suku ke 7 = 20 = a + 6b
a + 2b = 8
a + 6b = 20 (-)...eliminasi
-4b = -12
b = -12/-4 = 3
a + 2b = 8
a + 2(3) = 8
a + 6 = 8
a = 8 - 6 = 2
Sn = a + (n - 1)b
S15 = 2 + (15 - 1)×3
= 2 + 14 × 3
= 2 + 42
= 44 (A)