Помогите решить А)2(c-3)-3(4-c)=5. Б) 7+4(3-x)=5(x+2). В) 3(0,4a+3)-0,6a=3.

Ответ:

$2c - 6 - 12 + 3c = 5 \\ 5c - 18 = 5 \\ 5c = 23 \\ c = \frac{23}{5} = 4 \frac{3}{5} = 4.6$

Б)

$7 + 12 - 4x = 5x + 10 \\ 19 - 4x - 5x - 10 = 0 \\ - 9x + 9 = 0 \\ - 9x = - 9 \\ x = - 9 \div ( - 9)$

$x = 1$

В)

$1.2a + 9 - 0.6a = 3 \\ 0.6a + 9 = 3 \\ 0.6x =3 - 9 \\ 0.6x = - 6 \\ x = - 6 \div 0.6 = - 60 \div 6 \\$

$x = - 10$