A=55*[(1/11*16) * 1/5 + (1/16*21) * 1/5 + (1/21*26) * 1/5 + (1/26*31) * 1/5 + (1/31*36) * 1/5 + (1/36*41) * 1/5 ]
= 55* [ (1/11*16) + (1/16*21) + (1/21*26) + (1/26*31) + (1/31*36) + (1/36*41) ] * 1/5
= 55 * [ 1/11-1/16+1/16-1/21+1/21-1/26+1/26-1/31+1/31-1/36+1/36-1/41) * 1/5
= 55 * ( 1/11 - 1/41 ) * 1/5
= 30/41
A=55/11*16+55/16*21+55/21*26+55/26*31+55/31*36+55/36*41
55/11*16 +55/16*21 +55/21*26 +55/26*31+55/31*36 +55/36*41
Tinh: 55/11*16+55/16*21+55/21*26+55/26*31+55/31*36+55/36*41
Tính:
A=55/11*16+55/16*21+55/21*26+55/26*31+55/31*36+55/36*41
38/25+9/10-11/15+13/21-15/28+17/36-19/45+21/55=
31*55+31*55
A= 1/15 + 1/21 + 1/28 + 1/36 + 1/45 + 1/55
a) 5/9 * 12/25
b) 12/11 : 36/55
c) 9/55 * 22
d) 144/7 : 36
A= 1/3 + 1/6 + 1/10 + 1/15 + 1/21 +1/28 + 1/36 +1/45 + 1/55
