1082.
8 * 4/11+8 * 7/11=8(4/11+7/11)=8*11/11=8
5 * 1/7+5 * 6/7=5(1/7+6/7)=5*7/7=5
2/5 * 6/13+1/4 * 6/13=6/13 * (2/5+1/4)=6/13 * (8/20+5/20)=6/13 * 13/20=6/20=3/10
5/8 * 5/6 - 1/4 * 5/6=5/6 *(5/8 - 2/8)=5/6 * 3/8=5/16
1083.
(1/4)²=1²/4²=1/16
(3/8)²=9/64
(5/6)²=25/36
(2/7)²=4/49
(1 1/2)²=(3/2)²=9/4
(4 1/9)²=(37/9)²=1369/81
(6 2/3)²=(20/3)²400/9
(1/2)³=1/8
(2/3)³=8/27
(1/5)³=1/125
(4/9)³=64/729
(1 1/3)³=(4/3)³ =64/27
(2 1/4)³=(9/4)³=729/64
(3 1/2)³=(7/3)³=343/27
1084.
3/4 кг=1000:4*3=750 г
7/10 кг=1000:10*7=700 г
1 3/5 кг=1000 г+ 1000:5*3=1600 г
2 1/20 кг=2*1000 г+1000:20*1=2050 г
3 2/25 кг=3*1000+1000:25*2=3120 г
2/5 дм=10:5*2=4 см
3/10 дм=10:10*3=3 см
7/20 м=100:20*7=35 см
11/25 м=100:25*11=44 см
1 9/10 м=100*1 + 100:10*9=100+90=190 см
1/3 мин=60:3*1=20 сек
1/4 мин=60:4*1=15 сек
9/10 мин=60:10*9=54 сек
1/3600 ч=3600 : 3600 *1=1 сек
1/2 ч=3600 : 2*1=1800 сек