Question

решите уравнения:
1) -4x=4/7
2)-6x-12,6=0
3)6-0,7(3x+40)=x

Answer 1

Объяснение:

1)

$- 4x = \frac{4}{7} \\ x = - \frac{4}{7} \div 4 \\ x = - \frac{4}{7} \times \frac{1}{4} \\ x = - \frac{1}{7}$

2)

$- 6x - 12.6 = 0 \\ - 6x = 12.6 \div ( - 6)\\x = - 2.1$

3)

$6 - 0.7(3x + 40) = x \\ 6 - 2.1x - 28 = x \\ - 22 - 2.1x = x \\ - 2.1x - x = 22 \\ - 3.1x = 22 \\ x = - \frac{220}{31} = - 7 \frac{3}{31}$