Question

Tìm x

a) 3x – 2 = 19

b) [43 - (56 - x)].12 = 384

c) 3^x.2 + 15 = 33

Answer 1

a) 3x – 2 = 19

3x = 19 + 2

3x = 21

x = 21:3

x = 7

b) [43 - (56 - x)].12 = 384

43 – (56 – x) = 384:12

43 – (56 – x) = 32

56 – x = 43 – 32

56 – x = 11

x = 56 – 11

x = 45

c) 3^x.2 + 15 = 33

3^x.2 = 33 - 15

3^x.2 = 18

3^x = 18 : 2

3^x = 9

3^x = 33

x = 2.

Answer 2

a) 3x – 2 = 19

3x = 19 + 2

3x = 21

x = 21:3

x = 7

b) [43 - (56 - x)].12 = 384

43 – (56 – x) = 384:12

43 – (56 – x) = 32

56 – x = 43 – 32

56 – x = 11

x = 56 – 11

x = 45

c) 3^x.2 + 15 = 33

3^x.2 = 33 - 15

3^x.2 = 18

3^x = 18 : 2

3^x = 9

3^x = 33

x = 2.