bsr
1 - Trouver x sachant que : 7/x = 8
=> 7 = 8 * x
=> x = 7/8
2 - Trouver x sachant que : 1/6 = x/9
= 1 * 9 = 6 * x
=> 6x = 9
x = 9/6 = 1,5
3 - Trouver x sachant que : −4x = −7 × (−4)
- 4x = 28
x = 28 / (-4) = -7
4 - Trouver x sachant que : 34 = 4 − 6x
6x = 4 - 34
6x = -30
x = -30/6 = -5
5 - Trouver x sachant que : x = − (−3) −2 x −9
x = 3 - 2x - 9
x + 2x = -6
3x = -6
x = -2
