Решите: 2,4:(5/16 - (3/4)в квадрате) 3x+7y-6x-4y 8a+(5-a)-(7+11a) 4-5(3c+8) -3/5 x=15

Решите задачу:

$2.4 \div ( \frac{5}{16} - ( \frac{3}{4} ) {}^{2} ) \\ \\ \frac{12}{5} \div ( \frac{5}{16} - \frac{9}{16}) \\ \\ \frac{12}{5} \div ( - \frac{1}{4} ) \\ \\ - \frac{12}{5} \times 4 \\ \\ - \frac{48}{5 } \\ \\ - 9 .6 \\ \\ 3x + 7y - 6x - 4y \\ - 3x + 3y \\ - 3(x - y) \\ \\ 8a + (5 - a) - (7 + 11a) \\ 8a + 5 - a - 7 - 11a \\ - 4a - 2 \\ - 2(2a + 1) \\ \\ 4 - 5(3c + 8) \\ 4 - 15c - 40 \\ - 36 - 15c \\ \\ - \frac{3}{5} x = 15 \\ \\ - \frac{5}{3} \times ( - \frac{3}{5} x) = - \frac{5}{3 } \times 15 \\ \\ \frac{1}{3} \times 3x = - \frac{5}{3} \times 15 \\ \\ x = - \frac{5}{3} \times 15 \\ \\ x = - 5 \times 5 \\ x = - 25$