Question

2.52*【5又1/2-1.75*（2/3+9/21）】简便算法

要求是简便算法,很着急,帮忙了,吧步骤要写上啊

Answer 1

2.52*【5又1/2-1.75*（2/3+9/21）】

= 2.52*{11/2 - 175*(14/21 + 9/21)/100}

= 2.52*{11/2 - 7*25*23/2100}

= 2.52*{11*150/300 - 25*23/300}

= 2.52*(11*6 - 23)*25/300

= 2.52*43*25/300

= 252*43*25/30000

= 84*43*25/10000

= 21*43*4*25/10000

= 21*43/100

= [20*43 + 43]/100

= [860 + 43]/100

= 903/100

= 9.03

Answer 2

2.52*【5又1/2-1.75*（2/3+9/21）】
=2.52*【11/2-7/4*（14/21+9/21）】
=2.52*[66/12-23/12]
=2.52*43/12
=12*0.21*43/12
=0.21*43
=9.03

Answer 3

2.52*【5又1/2-1.75*（2/3+9/21）】
=2.52*{11/2-1.75*(14/21+9/21)}
=2.52*{5.5-1.75*23/21}
=2.52*(5.5-276)
=2.52*(-270.5)
=-681.66