解方程的题,急!谢谢!解方程：1/3｛1/7[1/5（x+2/3+4）+6]+8｝=31/5(x+15)=1/2-1/3

1.1/3｛1/7[1/5（x+2/3+4）+6]+8｝=3
1/7[1/5（x+2/3+4）+6]+8= 9
1/7[1/5（x+2/3+4）+6] = 1
1/5（x+2/3+4）+6 = 7
1/5（x+2/3+4） = 1
x+2/3+4 = 5
x = 1/3
2.1/5(x+15)=1/2-1/3(x-7)
6(x+15) = 15 - 10(x-7)
6x + 90 = 15 - 10x + 70
16x = -5
x = -5/16
3.1-(y-1)/2=2-(y+2)/5
10 -5(y-1) = 20 - 2(y+2)
10 - 5y + 5 = 20 - 2y - 4
-3y = 1
y = -1/3
4. 5/4[4/5(1/2y-3)-4/25]=1-y
5/4*4/5(1/2y-3)- 5/4 * 4/25 = 1-y
1/2y-3 - 1/5 = 1-y
3/2y = 21/5
y = 21/5 * 2/3 = 14/5

你能把它简化一下吗？乍一看我头都晕

1x+3x 等于15