6.3x2.3+7.7x2.1x3用簡便方法算

6.3x2.3+7.7x2.1x3用簡便方法算


6.3x2.3+7.7x2.1x3
=6.3*2.3+7.7*6.3
=6.3*(2.3+7.7)
=6.3*10
=63



5.1+5.7*5.1+5.1*3.3=?用簡便方法計算.很緊急!


5.1+5.7*5.1+5.1*3.3
=5.1*(1+5.7+3.3)
=5.1*10
=51



6/7÷3/2+2/3÷7用簡便方法計算


6/7×2/3+2/3×1/7
=2/3×(6/7+1/7)
=2/3



解方程2x/2x-1+x-1/x-2=2


x=1