Question

1) 4x-(2x-5)=21

2) 14x+5=8x+10

3) 15+5x=3x+30

4) 2x-5=15-3x

5) 2(3x+5)+3(x+1)=6x+20

6) 4(x-3)+5(x-3)=18

Answer 1

1) 4x-(2x-5)=21

4x-2x+5=21

2x+5=21

2x=21 -5

2x=16

x=16/2

x=8

Answer 2

2)14x+5=8x+10

14x-8x=10-5

6x=5

x=5/6

Answer 3

3) 15+5x=3x+30

5x-3x=30-15

2x=15

x=15/2

Vậy x=15/2

Answer 4

4) 2x-5=15-3x

2x+3x=15+5

5x=20

x=20:5

x=4

Vậy x=4

Answer 5

5) 2(3x+5)+3(x+1)=6x+20

6x+10+3x+3=6x+20

9x+13=6x+20

9x-6x=20-13

3x=7

x=7/3

Vậy x=7/3

Answer 6

6) 4(x-3)+5(x-3)=18

(x-3)(4+5)=18

(x-3).9=18

x-3=2

x=2+3

x=5

Vậy x=5