Tolongin nomor 3 ya makasih

=2X kali 3X kali 5X =1920
=30X³=1920
=X³=64
=X=4
Maka P=8,L=12,T=20
Luas permukaan balok=2((pxl)+(pxt)+(lxt))
=2((8x12)+(8x20)+(12x20))
=2(96+160+240)
=2(496)
=992cm²
Semoga ngebantu yaa

Pernandingan rusuk balok = 2 : 3 : 5
jumlah perbandingan = 2 + 3 + 5 = 10
V balok = 1920 cm^3
Misal jumlah seluruh rusuk = n
maka :
panjang = 5/10 × n = 5n/10 = n/2
lebar = 3/10 × n = 3n/10
tinggi = 2/10 × n = 2n/10 = n/5
V balok = plt
1920 = (n/2) × (3n/10) × (n/5)
1920 = (3n^3)/100
3n^3 = 1920 × 100
3n^3 = 192.000
n^3 = 192.000/3
n^3 = 64.000
n^3 = (40)^3
n = 40 cm

panjang = n/2 = 40/2 = 20 cm
lebar = 3n/10 = 3(40)/10 = 12 cm
tinggi = n/5 = 40/5 = 8 cm
maka L = 2pl + 2pt + 2lt
= 2×20×12 + 2×20×8 + 2×12×8
= 480 + 320 + 192
= 992 cm^2
Jadi luas seluruh permukaan balok adalah
992 cm^2