tolong bantu kerjakan sebisanya pake cara

17. K x n
phi.d x 250
22/7.21.250
66x250
16500 cm
......km

9.
x + y = 9
x - y = 1
______ -
2y = 8
y = 4

x + y = 9
x + 4 = 9
x = 5

HP = (5, 4)
19.
Panjang kawatnya
= 12 x 10
= 120 m

20.
luas karton
2 (30.20+30.15+20.15)
2 (600+450+300)
2 (1.350)
= 2.700 cm2

23.
Ds = akar 32 = 4 akar 2
s = 4 cm
Volume = 4 x 4 x 4 = 64 cm kubik