\(=\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+...+\frac{1}{10}\)có 9 p/số

\(=\frac{1}{10}.9=\frac{9}{10}\)

= 1/10 + 1/10 + ...................... + 1/10 có 9 phân số

= 1/10 x 9

= 9/10

ai tk mình mình đang bị âm điểm

9 / 12 bn nha

tk mk nha các bn

thanks nhiêu

\(\frac{5}{16}+\frac{5}{7}+0,4+\frac{1}{6}-\frac{4}{35}\)

= \(\frac{5}{16}+\frac{25}{35}+\frac{2}{5}+\frac{1}{6}-\frac{4}{35}\)

= \(\frac{5}{16}+\frac{2}{5}+\frac{1}{6}+\frac{25}{35}-\frac{4}{35}\)

= \(\frac{5}{16}+\frac{2}{5}+\frac{1}{6}+\frac{2}{3}\)

= \(\frac{5}{16}+\frac{2}{5}+\frac{5}{6}\)

= \(\frac{5}{16}+\frac{37}{30}\)

= \(\frac{371}{240}\)

\(=\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}+\)\(\frac{1}{10}\)

\(=\frac{1}{10}.9\)

\(=\frac{9}{10}\)

Đúng 100%

Đúng 100%

Đúng 100%

\(\frac{1}{10}+\frac{2}{20}+\frac{3}{30}+\frac{4}{40}+\frac{5}{50}+\frac{6}{60}+\frac{7}{70}+\frac{8}{80}+\frac{9}{90}\)

\(=\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}+\frac{1}{10}\)

\(=\frac{1}{10}\times9\)

\(=\frac{9}{10}\)

x + 1= 1

x= 1- 1

x= 0 

= x=0

 k cho 

a) 2/9 +1/5 +7/9+4/5

=( 2/9+7/9)+(1/5+4/5)

=1+1=2

b) 1/12+3/16+5/12+5/16

=(1/12 +5/12)+(3/16+5/16)

=1/2 +1/2=1

a \(\frac{7}{6}\)

b \(\frac{5}{3}\)

\(a,\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)

\(=\left(\frac{2}{5}+\frac{3}{5}\right)+\frac{1}{6}\)

\(=1+\frac{1}{6}\)

\(=\frac{7}{6}\)

Hok tốt!~

\(\frac{2}{5}+\frac{1}{6}+\frac{3}{5}\)

\(=\frac{2}{5}+\frac{3}{5}+\frac{1}{6}\)

\(=\frac{5}{5}+\frac{1}{6}\)

\(=1+\frac{1}{6}\)

\(=1\frac{1}{6}=\frac{7}{6}\)

Trả lời

Sửa đề câu a 1 tí

a)39/16:5/8-17/16:5/8+4/5

=(39/16-17/16):5/8+4/5

=11/8:5/8+4/5

=11/5+4/5

=15/5=3

b)16/17.12/19+16/17.7/19-2/3

=16/17.(12/19+7/19)-2/3

=16/17-2/3

=48/56-14/56

=34/56=17/28

Học tốt !

ágagrrafagf

cái này ko tính thuận tiện đc đou bn.

Bạn thử rút gọn các phân số đi

Sau đó bạn đi tính

Như vậy kết quả sẽ nhỏ hơn đấy

2/ \(\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}\)

\(=\left(1-\frac{1}{2}\right)+\left(1-\frac{1}{6}\right)+\left(1-\frac{1}{12}\right)+\left(1-\frac{1}{20}\right)+\left(1-\frac{1}{30}\right)+\left(1-\frac{1}{42}\right)\)

\(=\left(1+1+1+1+1+1\right)-\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\right)\)

\(=6-\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}\right)\)

\(=6-\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\right)\)

\(=6-\left(1-\frac{1}{7}\right)\)

\(=6-\frac{6}{7}=\frac{36}{7}\)

1, \(\left(1-\frac{1}{2}\right)+\left(1-\frac{1}{6}\right)+\left(1-\frac{1}{12}\right)+\left(1-\frac{1}{20}\right)\)

\(=\left(1+1+1+1\right)-\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}\right)\)

\(=4-\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}\right)\)

\(=4-\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}\right)\)

\(=4-\left(1-\frac{1}{5}\right)\)

\(=4-\frac{4}{5}=\frac{16}{5}\)

\(\frac{1}{2}+\frac{5}{6}+\frac{11}{12}+\frac{19}{20}+\frac{29}{30}+\frac{41}{42}\)

\(=1-\frac{1}{2}+1-\frac{1}{6}+1-\frac{1}{12}+1-\frac{1}{20}+1-\frac{1}{30}+1-\frac{1}{42}\)

\(=6-\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\right)\)

\(=6-\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}\right)\)

\(=6-\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}\right)\)

\(=6-\left(1-\frac{1}{7}\right)\)

\(=\frac{36}{7}\)