Ajutati-mă plss, toate ex de la 7 la 11

[tex]2 \times x - 1 \times 4 \times x + 1 \times 5 - x = 0 = > 2x - 4x + 5 - x = 0 = > - 3x + 5 = 0 = > - 3x = - 5 = > x = \frac{5}{3} [/tex]
[tex] 2 \times \frac{5}{3} - 1 + 4 \times \frac{5}{3} + 1 + 5 - \frac{5}{3} = \frac{10}{3} + \frac{20}{3} + 5 - \frac{5}{3} = \frac{40}{3} [/tex]