Решите уравнения:


1) 3x + 1 = 0
2) x + 4 = 7x - 3
3) 4(5-x) = 7(3-2x)
4)2/5(10x-5) = 7 - (6x+1)
5) 8 - x/3 = x + 4/4
6) 2x - 3/5 + 4x + 5/3 = 5x - 7/2