.75x4又3/4+4有3/4+4又3/4x4=（75+1+4）*4又3/4=80*4+80*3/4=320+60=3803/4x58+58除以4-64x1/4=1/4*58*3+1/4*58-64*1/4=1/4*（164+58-64）=1/4*158=39.5 73.8除以9+73.8除以1又1/8=73.8*1/9+73.8*8/9=73.8*（1/9+8/9...我不能采纳因为你起码有2题错了（1+1/2+1/3+1/4+1/5）x（1/2+1/3+1/4+1/5+1/6）-（1+1/2+1/3+1/4+1/5+1/6）x（1/2+1/3+1/4+1/5）令1/2+1/3+1/4+1/5=x 1/2+1/3+1/4+1/5+1/6=y原式=（1+x)*y-(1+y)*x=1+xy-1-xy =04.75x4又3/4+4有3/4+4又3/4x4又1/4=4.75*（4.75+1+4.25）=4.75*10=10 3/4x58+58除以4-64x1/4=1/4*58*3+1/4*58-64*1/4=1/4*（174+58-64）=1/4*168=42数字看不清