5/18+11/18-7/18 = (5+11-7)/18 = 9/18 = 0,5
D=10 дм
C=6,28 м.
C1=2pi*R=2piD/2=3,14*2*10/2=6,28*5=31,4
C1≠C Не Верно
Икс делим на икс это всегда один
Вычислите: 3/7+4/9, 8/9-78, 13/15-2/3, 20/21+3/7, 17/18-11/12, 7/16+1/6, 2/9+5/6, 10/21+9/14, 7/9-4/15, 9/14-3/7+15/28, 1/6+1/4-
bolshakoff [127]
3/7+4/9=27/63+28/63=55/63
8/9-78=8/9-702/9=-694/9=-77 цел 1/9
13/15-2/3=3/15-10/15=-7/15
20/21+3/7=20/21+9/21=29/21=1 цел 8/21
17/18-11/12=34/36-33/36=1/36
7/16+1/6=21/48+8/48=29/48
2/9+5/6==4/18+15/18=19/18=1цел 1/18
10/21+9/14=20/42+27/42=47/42=1цел 5/42
7/9-4/15=35/45-12/45=23/45
9/14-3/7+15/28=9/14-6/14+15/28=3/14+15/28=6/28+15/28=21/28=3/4=0,75
1/6+1/4-1/8=2/12+3/12-1/8=5/12-1/8=10/24-3/24=7/24
13/18-29/45+8/15=65/90-58/90+8/15=7/90+8/15=7/90+48/90=55/90=11/18