Question

（2÷3+3÷7+5÷21）÷21分之1÷0.28等于多少？要过程！

Answer 1

（2÷3+3÷7+5÷21）÷21分之1÷0.28
=（2÷3+3÷7+5÷21）×21÷0.28
=（2÷3×21+3÷7×21+5÷21×21）÷0.28
=（14+9+5）÷0.28
=28÷0.28
=100

Answer 2

解：（2÷3＋3÷7＋5÷21）÷1/21÷0.28
＝（2/3＋3/7＋5/21）×21×25/7
＝（2/3×21＋3/7×21＋5/21×21）×25/7
＝（14＋9＋5）×25/7
＝28×25/7
＝4×25
＝100

Answer 3

解：
原式=(2/3+3/7+5/21)*21/0.28
=[(2/3)*21+(3/7)*21+(5/21)*21]/0.28
=(14+9+5)/.028
=28/0.28
=100

Answer 4

（2÷3+3÷7+5÷21）÷21分之1÷0.28
=（2/3+3/7+5/21）*21/0.28
=（2/3+9/21+5/21）*3/0.04
=（2/3+14/21）*300/4
=（2/3+2/3）*300/4
=（4/3）*300/4
=300/3
=100

Answer 5

(2/3+3/7+5/21)/(1/21)*28/100=(14/21+9/21+5/21)*21*7/25=28/21*21*7/25=196/25=7.84