56个14分之3减去12的4分之3,差是多少?甲数是4分之3,乙数是12分之5,则甲乙两数和的7分之3是多少?2又6

56*3/14-12*3/4
=4*3-3*3
=3
(3/4+5/12)*3/7
=14/12 * 3/7
= 1/2
(2+1/6)*6*12/13
=(12+1)*12 / 13
=12
(6+4/5)*5/17
=(30+4)/17
=2
1/19*（3/4*19）
=1/19 * 3/4 *19
= 3/4