24*43分之51+51*43分之19=24*43分之51+19*43分之51=43分之51*(24+19)=43分之51*43=51
24×51/43+51×19/43=1/43×(24×51+51×19)=1/43×[51×(24+19)]=1/43×51×43=51×1/43×43=51