77, 78,79 plsssssssss

Bonsoir,

77) x + 5 + 3x = 13
x + 3x = 13 - 5
4x = 8
x = 8/4
x = 2

14x - 13 = - 4 + 8x
14x - 8x = - 4 + 13
6x = 9
x = 9/6
x = 3/2

78) 11x - 2 = - x - 4
11x + x = - 4 + 2
12x = - 2
x = - 2/12
x = - 1/6

3x + 2 = - 7 - 9x
3x + 9x = - 7 - 2
12x = - 9
x = - 9/12
x = - 3/4

79) 5x + 8x = - 11x - 6
5x + 8x + 11x = - 6
24x = - 6
x = - 6/24
x = - 1/4

2 + 5x - 19x + 1 = - 13x + 18 + 9x
5x - 19x + 13x - 9x = 18 - 2 - 1
- 10x = 15
x = - 15/10
x = - 3/2