幫忙計算下,能簡算就簡算 1-(3又1/2-2又1/2÷1又1/4)*4/9 2000÷5/21-3又1/5*2000 [0.186+(1又3/4-1/2)-0.186-1又1/4]+45 7/10÷(1-3/4*0.4)

幫忙計算下,能簡算就簡算 1-(3又1/2-2又1/2÷1又1/4)*4/9 2000÷5/21-3又1/5*2000 [0.186+(1又3/4-1/2)-0.186-1又1/4]+45 7/10÷(1-3/4*0.4)

1-(7/2-5/2*4/5)*4/9=1/3
2000*21/5-16*2000/5=2000/5*(21-16)=2000
[0.186-0.186+(1又3/4-1又1/4)-1/2]+45=45
7/10÷(1-3/4*4/10)=1