六年级上册的数学寒假作业 好难哦 求x的值

0.6:百分之36=4/5:x
0.6x=0.36×0.8
0.6x=0.288
x=0.48

4/x+3=0.5
4=0.5×(x+3)
0.5x+1.5=4
0.5x=4-1.5
0.5x=2.5
x=5

(3.8-x):7=2/7
3.8-x=2/7×7
3.8-x=2
2+x=3.8
x=3.8-2
x=1.8

8:5+x/4=4:5
(5+4/x)×4=8×5
20+x=40
x=40-20
x=20

0.6:36%=4/5:x
0.6x=0.36×0.8
0.6x=0.288
x=0.48

4/x+3=0.5
0.5×(x+3)=4
0.5x+1.5=4
0.5x=4-1.5
0.5x=2.5
x=5

(3.8-x):7=2/7
3.8-x=2/7×7
3.8-x=2
2+x=3.8
x=3.8-2
x=1.8

8:5+x/4=4:5
(5+4/x)×4=8×5
20+x=40
x=40-20
x=20