Решите уравнение: a) 8x + 7x = 1515; б) 8 × (2x – 6) = 128.

a)

$$8x + 7x = 1515$$

$$15x = 1515$$

$$x = \frac{1515}{15}$$

$$x = 101$$

б)

$$8 \cdot (2x - 6) = 128$$

$$2x - 6 = \frac{128}{8}$$

$$2x - 6 = 16$$

$$2x = 16 + 6$$

$$2x = 22$$

$$x = \frac{22}{2}$$

$$x = 11$$