= 0,25 : 0,5 - 3/4

= 1/4 : 1/2 - 3/4

= 1/2 - 3/4

= -1/4

`0,25 :(10,3 - 9,8) - 3/4`

`= 0,25 : 0,5 - 0,75`

`= 0,5 - 0,75`

`= -0,25`

\(=\frac{1}{4}:\frac{1}{2}-\frac{3}{4}=\frac{1}{2}-\frac{3}{4}=-\frac{1}{4}\)

\(0,25:\left(10,3-9,8\right)-\frac{3}{4}\)

= 0,25:0,5-\(\frac{3}{4}\)

= 0,5-\(\frac{3}{4}\)

= \(\frac{1}{2}-\frac{3}{4}\)

= \(\frac{2-3}{4}\)

= \(\frac{-1}{4}\)

a) ( \(\frac{3}{8}\)+\(\frac{-1}{4}\)+\(\frac{5}{12}\)): \(\frac{2}{3}\)

=(\(\frac{9}{24}\)+\(\frac{-6}{24}\)+\(\frac{10}{24}\)):\(\frac{2}{3}\)

=\(\frac{13}{24}\):\(\frac{2}{3}\)

=\(\frac{13}{16}\)

Câu b) bn tự làm nha , mik đg có việc bận r ....Chúc bn làm tốt

Thế mà không làm được

a) \(\left(\frac{7}{8}-\frac{3}{4}\right)\cdot\frac{1}{3}-\frac{2}{7}\cdot\left(3,5\right)=\left(\frac{7}{8}-\frac{3}{4}\right)\cdot\frac{1}{3}-\frac{2}{7}\cdot\frac{7}{2}\)

\(=\left(\frac{7}{8}-\frac{6}{8}\right)\cdot\frac{1}{3}-1=\frac{1}{8}\cdot\frac{1}{3}-1=\frac{1}{24}-\frac{24}{24}=-\frac{23}{24}\)

b) \(\left(\frac{3}{5}+0,415-\frac{3}{200}\right)\cdot2\frac{2}{3}\cdot0,25\)

\(=\left(\frac{3}{5}+\frac{83}{200}-\frac{3}{200}\right)\cdot\frac{8}{3}\cdot\frac{1}{4}\)

\(=\left(\frac{3}{5}+\frac{80}{200}\right)\cdot\frac{8}{3}\cdot\frac{1}{4}=\left(\frac{3}{5}+\frac{2}{5}\right)\cdot\frac{8}{3}\cdot\frac{1}{4}=1\cdot\frac{8}{3}\cdot\frac{1}{4}=1\cdot\frac{2}{3}\cdot\frac{1}{1}=\frac{2}{3}\)

c) \(\frac{5}{16}:0,125-\left(2\frac{1}{4}-0,6\right)\cdot\frac{10}{11}\)

\(=\frac{5}{16}:\frac{1}{8}-\left(\frac{9}{4}-\frac{3}{5}\right)\cdot\frac{10}{11}\)

\(=\frac{5}{16}\cdot8-\frac{33}{20}\cdot\frac{10}{11}=\frac{5}{2}-\frac{3}{2}=1\)

d) \(0,25:\left(10,3-9,8\right)-\frac{3}{4}=\frac{1}{4}:\left(\frac{103}{10}-\frac{98}{10}\right)-\frac{3}{4}\)

\(=\frac{1}{4}:\frac{1}{2}-\frac{3}{4}=\frac{1}{4}\cdot2-\frac{3}{4}=\frac{2}{4}-\frac{3}{4}=-\frac{1}{4}\)

Câu cuối tương tự

c) x=-2 nha

d) =\(\frac{1}{5.6}\)+\(\frac{1}{6.7}\)+......+\(\frac{1}{11.12}\)

=\(\frac{1}{5}\)-\(\frac{1}{6}\)+\(\frac{1}{6}\)-\(\frac{1}{7}\)+.....+\(\frac{1}{11}\)-\(\frac{1}{12}\)

=\(\frac{1}{5}\)-\(\frac{1}{12}\)= \(\frac{7}{60}\)

bạn ơi kết quả là 7/60

\(=\frac{1}{5.6}+\frac{1}{6.7}+...+\frac{1}{11.12}\)

\(=\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+...+\frac{1}{11}-\frac{1}{12}\)

\(=\frac{1}{5}-\frac{1}{12}\)

\(=\frac{7}{60}\)

Bài làm

a) \(\left(\frac{3}{8}+\frac{-1}{4}+\frac{5}{12}\right):\frac{2}{3}\)

\(=\left(\frac{9}{24}+\frac{-6}{24}+\frac{10}{24}\right).\frac{3}{2}\)

\(=\frac{13}{24}.\frac{3}{2}\)

\(=\frac{39}{48}\)

b) \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+1\frac{5}{7}\)

\(=-\frac{5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{12}{7}\)

\(=-\frac{5}{7}.1+\frac{12}{7}\)

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

\(=1\)

c) \(0,25:\left(10,3-9,8\right)-\frac{3}{4}\)

\(=\frac{25}{100}:\left(0,5\right)-\frac{3}{4}\)

\(=\frac{5}{4}:\frac{1}{2}-\frac{3}{4}\)

\(=\frac{5}{4}.2-\frac{3}{4}\)

\(=\frac{5}{2}-\frac{3}{4}\)

\(=\frac{10}{4}-\frac{3}{4}=\frac{7}{4}\)

d) \(-\frac{5}{9}.\frac{13}{28}-\frac{13}{28}.\frac{4}{9}\)

\(=-\frac{13}{28}\left(\frac{5}{9}+\frac{4}{9}\right)\)

\(=-\frac{13}{28}.\frac{9}{9}\)

\(=-\frac{13}{28}.1\)

\(=-\frac{13}{28}\)

a;[(0,4+1,15-9/20]:0,1]:(3 va 1/6 +2 va 1/3)

=(11/10:1/10):11/2

=11:11/2

=2

b,[0,25:(10,3-9,8)-3/4]:[(3/8+5/12-1/4):1/36.24]

=(0,25:53/24-3/4):(13/24:1/36.24)

=-135/212:4̉́̉̉68

=-15/11024

nho tik nha

a,(3/5+0,415-3/200).\(2\dfrac{2}{3}\).0,25

=(0,6+0.415-3/200)8/3.1/4

=(1,015-3/200).8/3.1/4

=(1015/1000-3/200).2/3

=(203/200-3/200).2/3

=1.2/3=2/3

b,0,25:(10,3-9,8)-3/4

=0,25:910,3-9,8)-0.75

=0,25:0,5-0,75

=-0,25

Mình làm từng đó trước,lần sau mình sẽ lm típ nha!