Question

Tìm số nguyên x, biết:

a) 2.x + 1 = 3

b) (2x - 5) + 17 = 6

c) 10 - 2. (4 - 3x) = -4

Answer 1

a) 2x + 1 = 3

2x = 2

x = 1

b) ( 2x - 5 ) + 17 = 6

( 2x - 5 ) = 6 - 17

( 2x - 5 ) = -11

2x = -11 + 5

2x = -6

x = -3

c) 10 - 2 x ( 4 - 3x ) = -4

2 x ( 4 - 3x ) = 14

4 - 3x = 7

3x = -3 

x = -1 

Answer 2

a) 2x + 1 = 3

2x = 3-1

2x=2

x=2:2

x=1

Answer 3

b) ( 2x - 5 ) + 17 = 6

( 2x - 5 ) = 6 - 17

( 2x - 5 ) = -11

2x = -11 + 5

2x = -6

x=-6:2

x = -3

 

Answer 4

c) 10 - 2 x ( 4 - 3x ) = -4

2 x ( 4 - 3x ) = 14

4 - 3x = 7

3x=4-7

3x = -3 

x = -1