Tìm x, biết:

a) 8 – 3(7 + x) = 64

b) 131.x – 941 = 2⁷.2³

c) 12.(x – 1) : 3 = 4³ + 2³

a) 88 – 3.(7 + x) = 64

3.(7 + x) = 88 − 64

3.(7 + x) = 24

7 + x = 24 : 3

7 + x = 8

x = 8 − 7

x = 1

Vậy x = 1.

b) 131.x – 941 = 2⁷.2³

131x – 941 = 2¹⁰

131x = 1024 + 941

131x = 1965

x = 1965 : 131

x = 15

Vậy x = 15

c) 12.(x – 1) : 3 = 4³ + 2³

12.(x – 1) : 3 = 64 + 8

12.(x – 1) : 3 = 72

12.(x – 1) = 72.3

12(x – 1) = 216

x – 1 = 216 : 12

x – 1 = 18

x = 19

Vậy x = 19.