(11*2/13+13*2/11)/(5/11+5/13)
=[(2+11*13)/13+(2+11*13)/11]/[5*(11+13)/(11*13)]
={(11+13)*(2+11*13)/(11*13)]/[5*(11+13)/(11*13)](约分)
=(2+11*13)/5
=29
=(3480/143)/(120/143) 【前面的带分数换算成假分数相加】【后面的通分相加】→【分母都为143】
=(3480/143)*(143/120) 【143约去】→【结果=3480/120】
=29
好的话要加分哦!亲~
=[(11*13+2)*(1/11+1/13)]/[5*(1/11+1/13)]
=(11*13+2)/5
=145/5
=29
29