maths(about 方程式)

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

2) 0.4-0.6(x-3)=(1/3)x - 3/5(x-7)
2/5-3/5(x-3)=(1/3)x - 3/5(x-7)
6-9(x-3)=5x-9(x-7)
6-9x+27=5x-9x+63
5x=-30
x=-6

1) x = 1/4

2) x = -6