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2 x + 3 = 10 - 5 x

tu testes les solutions proposées

si x = - 1

2 * -1 + 3 = 10 - 5 * - 1

- 2 + 3 = 10 + 5

1 ≠ 15  donc  - 1  n'est pas solution

si  x = 0

0 *2 + 3 = 10 - 5 * 0

3 ≠ 10  donc  0 n'est pas solution

si x =  1

2 * 1 + 3 = 10 - 5 * 1

2 + 3 = 10 - 5

5  = 5  donc  1  est solution  

x + 17  = 32

x = 32  - 17

x = 15

x - 21 = 19

x  = 19 + 21

x  = 40

8 a  = 112

a = 112/8 =  14

t /7 = 23

t = 23*7 =  161

5 x + 4 = 32

5 x = 32 - 4

5 x = 28

x = 28/5  = 5.6

- 4 x - 7 = 61

- 4 x =  61 + 7

- 4 x = 68

x = - 68/4  = - 17

6 x - 4 = 3 x + 14

6 x - 3 x = 14 + 4

3 x = 18

x = 6

9 - 2 x = 11 + 4 x

- 2 x - 4 x = 11 - 9

- 6 x = 2

x = - 2/6 = - 1/3