a)
[tex] \frac{x - 6}{3} = 5 | \times 3 \\ x - 6 = 15 \\ x = 21[/tex]
b)
[tex]3(2x + 1) = 6 \\ 6x + 3 = 6 \\ 6x = 3 | \div 6 \\ x = \frac{1}{2} [/tex]
c)
[tex](x + 6) + (2x - 1) = 8 \\ x + 6 + 2x - 1 = 8 \\ 3x = 8 - 6 + 1 \\ 3x = 3 | \div 3 \\ x = 1[/tex]
d)
[tex]2(x - 6) + 3(x + 7) = 2x - 1 \\ 2x - 12 + 3x + 21 = 2x - 1 \\ 5x - 2x = - 1 + 12 - 21 \\ 3x = - 10 | \div 3 \\ x = - \frac{10}{3} = - 3 \frac{1}{3} [/tex]
e)
[tex]2x - 1 = 7 \\ 2x = 8 | \div 2 \\ x = 4[/tex]
