tolongsiiii no 1-3pake caranya plisssss

1) panjang lilin yg meleleh
= 25 cm - 15 cm
= 10 cm
waktu meleleh = 20 menit
kec = panjang lilin ÷ waktu
= 10 cm ÷ 20 mnt
= ½ cm/mnt
= 0,5 cm/mnt

2) misal nilai ke 6 = a
8 = (5 × 7,6) + a / 6
8 × 6 = 38 + a
48 = 38 + a
a = 48 - 38
a = 10
jadi nilai ulangan ke 6 harus 10

3) x = (5 × 7,6) + (4 × 8) / 9
x = 38 + 32 / 9
x = 70 / 9
x = 7,8