1)AB/AD=BC/DC
AB/AD=BC/(AC-AD)
10/AD=15/(20-AD)
200-10AD=15AD
25AD=200
AD=8
CD=20-8=12
2)AB/AD=BC/DC
16/8=BC/5
8BC=80
BC=10
1) (540/60+231)/15-1000/8/25 = 11
По действиям:
1. 540/60+ 231= 9 + 231 = 240
2. 240/15 = 16
3. 1000/8 = 125
4. 125/25 = 5
5. 16 - 5 = 11
2) 12900/100-(500-350/7*9) = 79
1.350/7=50
2.50*9=450
3.500-450=50
4.12900/100=129
5.129-50=79
3) (810/3-120)/6+8*(172/4-20) = 209
1.810/3-120=270-120=150
2.150/6=25
3.172/4-20=43-20=23
4.8*23=184
5. 25+184=209
4) (25812*3-109*4)/1000 = 77
1. 25812*3=77436
2.109*4=436
3. 77436-436=77000
4. 77000/1000=77
<span>5) (345.720-72.045*4)/10*3=1,918
</span>1. 72,045*4=288,18
2. 345,720 - 288,18 = 57,54
3. 10*3 = 30
4. 57,54/30=1,918
( 5/6-2/9):11= 1/18
1) 5/6-2/9= 15/18- 4/18= 11/18
<span>2) 11/18: 11= 11/18* 1/11=1/18</span>