能巧算的要巧算:(1 ) 8.64/{64.8-(48.6-2.7*2)} (2 ) 3.7*4.7+6.3*3.7 ( 3 ) 2.5*1.9+25*0.71+0.25*
问题描述:
能巧算的要巧算:(1 ) 8.64/{64.8-(48.6-2.7*2)} (2 ) 3.7*4.7+6.3*3.7 ( 3 ) 2.5*1.9+25*0.71+0.25*
答
8.64/{64.8-(48.6-2.7*2)} 这个题目好象也不完整
=8.64/21.6
=3/7
3.7*4.7+6.3*3.7
=3.7(4.7+6.3)
=3.7*10
=37
2.5*1.9+25*0.71+0.25 *10(这个题目不完整把,我想后面应该是个10)
=2.5*1.9+2.5*7.1+2.5*1
=2.5*(1.9+7.1+1)
=2.5*10
=2.5