Помогите 2/5 * 7/12 5*2/7 , 7/20 * 10/13*26 , 1 1/4* 2 2/7

Question

Помогите 2/5 * 7/12

5*2/7 , 7/20 * 10/13*26 , 1 1/4* 2 2/7

Comments

2/5 * 7/12=7/305*2/7=10/7=1 3/7 ; 7/20 * 10/13*26 =7; 1 1/4* 2 2/7=5/4*16/7=20/7=2 6/7

Answer 1

1) 2/5*7/12=(2*7)/(5*12)=14/60=7/30
2) 5*2/7=(5*2)/7=10/7=1 3/7
3) 7/20*10/13*26=(7*10*26)/20*13=1820/260=7
4) 1 1/4*2 2/7=5/4*16/7=(5*16)/(4*7)=80/28=2 24/28=2 6/7

Comments

неверно =80/21=3 17/21 (не 21 а 28)