C1 : \(85,35:5+63,05:5=17,07+12,61\)

                                           \(=29,68\)

C2 :  \(85,35:5+63,05:5=\left(85,35+63,05\right):5\)

                                           \(=148,4:5=29,68\)

Cách 1:

85,35 : 5 + 63,05 : 5

= 17,07 + 12,61

= 29,68

Cách 2 :

85,35 : 5 + 63,05 : 5

= ( 85,35 + 63,05 ) : 5

= 148,4 : 5

= 29,68

^_^ hok tốt ^_^

`#3107.101107`

`85,35 \div 5 + 63,05 \div 5`

`= 17,07 + 12,61`

`= 29,68`

____

`85,35 \div 5 + 63,05 \div 5`

$= 85,35 \times \dfrac{1}{5} + 63,05 \times \dfrac{1}{5}$

$= \dfrac{1}{5} \times (85,35 + 63,05)$

$= \dfrac{1}{5} \times 148,4$

$= 0,2 \times 148,4$

$= 29,68$

Cách 1:

85,35 : 5 + 63,05 : 5

=17,07 + 12,61

=29,68

Cách 2:

85,35 : 5 + 63,05 : 5

= (85,35+63,05) :5

=148,4 : 5

=29,68

C1 = ( 85,35 + 63,05 ) : 5

     = 148,4 : 5

     = 29,68

C2 : = 17,07 + 12,61

        = 29,68

Hok tốt

85, 35 : 5 + 63, 05 : 5

C1: = 17, 07 + 12, 61

      = 29, 68

C2 = ( 85, 35 + 63, 05 ) : 5

      = 148,4 : 5

      -= 29, 68

Bài làm

Cách 1: 85,35:5+53,05:5

          = 17,07 + 10,61

          = 27,68

Cách 2:  85,35:5+53,05:5

            = (85,35+53,05): 5

            =      138,4         : 5

            = 27,68

# Chúc bạn học tốt #

~ Yêu bạn, Nguyễn Thị Phương Anh ~

Answer:

Cách 1:

Số số hạng:

\(\left(999-1\right):2+1=500\) số hạng

Tổng:

\(\left(999+1\right).500:2=250000\)

Cách 2:

\(1+3+5+7+...+997+999\)

\(=\left(1+999\right).[\left(999-1\right):2+1]:2\)

\(=1000.500:2\)

\(=250000\)

mk chỉ biết làm cách 1

= ( 2015-1):2+1=1008

= ( 2015+1).1008:2=1016064

ko biết đúng ko

c1                           {3/4+1/2}*5/7

                               =5/4*5/7

                               =25/28 

c2                          {3/4+1/2}*5/7

                               = 3/4*5/7+1/2*5/7

                               =15/28+5/14

                               =25/28

\((\frac{3}{5}+\frac{2}{5})+(\frac{4}{7}+\frac{1}{7}+\frac{2}{7})\) ) =1+1=2

\(\frac{3}{5}\times\frac{7}{21}+\frac{7}{21}\times\frac{2}{5}=\frac{7}{21}\times\left(\frac{3}{5}+\frac{2}{5}\right)=\frac{1}{3}\times\left(\frac{3}{5}+\frac{2}{5}\right)=\frac{1}{3}\times1=\frac{1}{3}\)

   Học tốt !

\(\frac{3}{5}\cdot\frac{7}{21}+\frac{7}{21}+\frac{2}{5}\)

\(=\frac{7}{21}\cdot(\frac{3}{5}+\frac{2}{5})\)

\(=\frac{7}{21}\cdot1=\frac{7}{21}=\frac{1}{3}\)

C1  \(\frac{3}{5}.\frac{7}{21}+\frac{7}{21}.\frac{2}{5}\)

\(=\frac{7}{21}\left(\frac{3}{5}+\frac{2}{5}\right)\)

\(=\frac{7}{21}.1\)

\(=\frac{7}{21}=\frac{1}{3}\)

C2   \(\frac{3}{5}.\frac{7}{21}+\frac{7}{21}.\frac{2}{5}\)

\(=\frac{3.7}{5.21}+\frac{7.2}{21.5}\)

\(=\frac{21}{105}+\frac{14}{105}\)

\(=\frac{35}{105}\)

\(=\frac{7}{21}=\frac{1}{3}\)