2分之1*3+2分之1*5+2分之1*2
=1/2x(3+5+2)
=1/2x10
=5
（6分之1+8分之1）*24
=1/6x24+1/8x24
=4+3
=7
9分之7/5分之11+11分之5*9分之2
=7/9x5/11+5/11x2/9
=(7/9+2/9)x5/11
=5/11
6x+3分之2x=9
20/3x=9
x=9x3/20
x=27/20
如果本题有什么不明白可以追问,