18X-27=117还有70%X+20%X=3.625%+10X=4/5先化简，再求比值0.75:3/421:0.71/

18X-27=117
18x = 144
x = 8
70%X+20%X=3.6
90%x=3.6
0.9x=3.6
x=4
25%+10X=4/5
0.25+10x=0.8
10x = 0.55
x = 0.055
0.75:3/4=0.75：0.75 = 1:1 = 1
21:0.7 = 30:1 =30
1/3:36/45 = 1/3 ：4/5 = 5/15:12/15 = 5:12 = 5/12
17:51/100 = 1700:51 = 100:3 = 100/3
不理解就追问,理解了请采纳!

18x=117+27 x=8
0.7x+0.2x=3.6 0.9x=3.6 x=4
10x=0.8-0.25=0.55 x=0.055
0.75=3/4 (3/4):(3/4)=1
0.7=7/10 21:(7/10)=21*(10/7)=30
36/45=4/5 1/3:4/5=1/3*(5/4)=5/12
17*(100/51)=300

18X-27=117
18X=117+27
18X=177
X=8

18X-27=117 ,x=8
70%X+20%X=3.6 x=8
25%+10X=4/5 x=11/200
0.75:3/4 化简3/4:3/4=1
21:0.7 21:7/10=30
1/3:36/45 15/45:36/45=5/12
17:51/100 1700/100:51/100=1700/51