請幫幫我吧!小五分數加減~10點!!

1.四又三分之二加二又四分之一加一又十分之七=?
4(2/3) + 2(1/4)+1(7/10)
=(4x3+2)/3 + (2x4+1)/4 + 17/10
=517/60
=8又60分37

2.七又四分之三減三又六分之五加二又九分之二=?
=(7x4+3)/4-(3x6+5)/6 +(2x9+2)/9
=221/36
=6又36分5

3.家樂比珊珊重五又五分之四公斤, 珊珊又比子明輕四又六分之一公斤。
已知子明重四十二又二分之一公斤, 家樂的體重是多少公斤?
let ka lok = k
shan shan =s
chi man = c

k-s =(5x5+4)/5 = 29/5kg ...(1)
c-s = (4x6+1)/6 = 25/6 kg...(2)
'.' c = (42x2+1)/2= 42.5kg
.'. (1)-(2),
k-c-s+s=29/5-25/6
k= 42.5+5.8 -25/6
= 44又15分2公斤