急。。。谁能给我出20道分数乘法简算！！！

(1/2+2/3)*6=1/2*6+2/3*6=3+4=7
(2/3+3/4)*12=2/3*12+3/4*12=8+9=17
(1/3+1/4)*12=1/3*12+1/4*12=4+3=7
(1/4+1/5)*20=1/4*20+1/5*20=5+4=9
(2/3+2/5)*15=2/3*15+2/5*15=10+6=16
(3/4+1/2)*4=3/4*4+1/2*4=3+2=5
(10/11+12/10)*110=10/11*110+12/10*110=100+132=232
(2/5+2/7)*35=2/5*35+2/7*35=14+10=24
(3/5+3/7)*35=3/5*35+3/7*35=21+15=36
(4/5+5/6)*30=4/5*30+5/6*30=24+25=49
(5/7+5/8)*56=5/7*56*5/8*56=40+35=75
(8/9+9/10)*90=8/9+90*9/10*90=80+81=161
(11/12+6/5)*60=11/12*60+6/5*60=55+72=127
(9/5+9/4)*20=9/5*20+9/4*20=36+45=81
(4/7+5/6)*42=4/7*42+5/6*42=24+35=59
(3/8+2/9)*72=3/8*72+2/9*72=24+16=40
(1/11+1/15)*165=1/11*165+1/15*165=15+11=26
(1/20+1/30)*60=1/20*60+1/30*60=3+2=5
(2/31+3/62)*62=2/31*62+3/62*62=4+3=7
(11/16+13/32)*32=11/16*32+13/32*32=22+13=35