①4+0.7x=102
②
③7:x=2.3:6.9
80×20%= 200×9%= 3.6×50%= 100×25%=
3.14×5= 5²×3.14= 2²×3.14= 3.14×9=
10-0.76=
2÷10%=
1-1÷7=
×8=
÷=
5-=
×÷×=
12.3÷0.1=
140÷70%=
0.41-0.32=
0.8a+0.5a=
⑴3.64-2.25+6.36-2.75 ⑵
⑶4÷5+39× ⑷20.24×2023-20.22×2024
①85×+15×75%
②2.7÷(4-82%﹣18%)
③(-75%)÷(50%+)
④0.55×8-60%
⑤+(50%-)÷
问:这两条绳子原来的长度是多少厘米?