TOLONG JAWAB SECEPATNYA BISA HARI INI No 1-8...untuk ulangan besok....ada cara dan harus benar (materi balok)

1. p : l : t = 5 : 4 : 3
p = 5x
l = 4x
t = 3x
V = 1620 cm^3

V = p × l × t
1620 = 5x × 4x × 3x
1620 = 60x^3
x^3 = 1620 ÷ 60
x^3 = 27
x = akar3 dari 27
x = 3 cm

p = 5x = 5 (3) = 15cm
l = 4x = 4 (3) = 12 cm
t = 3x = 3 (3) = 9 cm


2. V = 120 cm^3
p = 6 cm
l = 5 cm

V = p × l × t
120 = 6 × 5 × t
120 = 30 t
t = 120 ÷ 30
t = 40 cm

3. Lp = 198 cm^2
l = 6 cm
t = 3 cm

Lp = 2 (pl + pt + tl)
198 = 2 (6p + 3p + 18)
198 = 2 (9p + 18)
9p + 18 = 198 ÷ 2
9p + 18 = 99
9p = 99 - 18
9p = 81
p = 81 ÷ 9
p = 9 cm


4. Vair -> t = 2/3t
t = 50 cm
l = 70 cm
p = 90 cm

Vair = p × l × 2/3 t
Vair = 90 × 70 × 2/3 × 50
Vair = 210.000 cm^3
Vair = 210 dm^3

1 dm^3 = 1 liter
210 dm^3 = 210 liter air


5. V = 6l = 6 dm^3 = 6.000 cm^3
p = 15 cm
l = 10 cm

V = p × l × t
6.000 = 15 × 10 × t
6.000 = 150t
t = 6.000 ÷ 150
t = 40 cm


6. p = 10 cm
l = 15 cm
t = 1 m = 100 cm

V = p × l × t
V = 10 × 15 × 100
V = 15.000 cm^3
V = 15 dm^3 = 15 liter

Harga beras = Rp 8.000/liter

Total harga beras
= 15 × Rp 8.000
= Rp 120.000


7. Balok A = 12 × 6 × 7
Balok B = 6 × 3 × 4

Perbandingan Volume
VA : VB
= (12 × 6 × 7) : (6 × 3 × 4)
= 504 : 72
= 7 : 1