5x-1=8-2x x+7x-12=14-3x+7 7u+u9-4-12=6u-15

5x-1=8-2x
5x+2x=8+1
7x=9
x=9/7

x+7x-12=14-3x+7
x+7x+3x=14+7+12
11x=33
x=33/11 ou 3
 
7u+9u-4-12=6u-15
7u+9u-6u=-15+4+12
10u=1
u=1/10

5x - 1 = 8 - 2x
5x + 2x = 8 + 1
7x = 9
x = 9/7

x + 7x - 12 = 14 - 3x + 7
x + 7x + 3x = 14 + 7 + 12
8x + 3x = 21 + 12
11x = 33
x = 3

7u + 9u - 4 - 12 = 6u - 15
7u + 9u - 6u = 4 + 12 - 15
16u - 6u = 16 - 15
10u = 1
u= 1/10