c)
[tex] \frac{x + 2}{9} + \frac{x - 1}{3} = 1 | \times 9 \\ x + 2 + 3x - 3 = 9 \\ 4x = 9 + 3 - 2 \\ 4x = 10 | \div 4 \\ x = \frac{10}{4} [/tex]
d)
[tex] \frac{2x + 3}{5} = \frac{2 - x}{3} + x | \times 15 \\ 6x + 9 = 10 - 5x + 15x \\ 6x + 5x - 15x = 10 - 9 \\ - 4x = 1 | \div ( - 4) \\ x = - \frac{1}{4} [/tex]