\(\dfrac{3}{15}-\dfrac{5}{35}=\dfrac{1}{5}-\dfrac{1}{7}=\dfrac{7}{35}-\dfrac{5}{35}=\dfrac{2}{35}\)

1/5-1/7= 7/35-5/35=2/35

3/15 - 5/35 = 1/5 - 1/7 = 7/35 - 5/35 = 2/35

3/15 - 5/35 

= 1/5 - 1/7

= 2/35

3/15-5/35=1/5-5/35=7/35-5/35=2/35

\(\frac{3}{15}-\frac{5}{35}=\frac{1}{5}-\frac{1}{7}=\frac{7}{35}-\frac{5}{35}=\frac{2}{35}\)

a) \(\dfrac{16}{24}-\dfrac{1}{3}=\dfrac{2}{3}-\dfrac{1}{3}=\dfrac{1}{3}\)

b ) \(\dfrac{4}{5}-\dfrac{12}{60}=\dfrac{4}{5}-\dfrac{1}{5}=\dfrac{4}{5}\)

c ) \(\dfrac{35}{50}-\dfrac{3}{10}=\dfrac{7}{10}-\dfrac{3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)

d ) \(\dfrac{21}{28}-\dfrac{1}{4}=\dfrac{3}{4}-\dfrac{1}{4}=\dfrac{2}{4}=\dfrac{1}{2}\)

3/15 - 5/35

= 1/5 - 1/7

= 2/35

\(\frac{3}{15}\)-\(\frac{5}{35}\)=\(\frac{1}{5}\)-\(\frac{1}{7}\)

\(\frac{1}{5}\)- \(\frac{1}{7}\) = \(\frac{7}{35}\)- \(\frac{5}{35}\)= \(\frac{7-5}{35}\)=\(\frac{2}{35}\)

tick nhé

\(\frac{5}{7}-\frac{4}{17}=\frac{5}{7}-\frac{2}{8,5}=\frac{42,5}{59,5}-\frac{14}{59,5}=\frac{38,5}{59,5}\)

\(\frac{21}{27}-\frac{2}{9}=\frac{7}{9}-\frac{2}{9}=\frac{5}{9}\)

\(\frac{13}{5}-\frac{35}{25}=\frac{13}{5}-\frac{7}{5}=\frac{6}{5}\)

chắc ko hả bạn vip à nghi quá chắc ko được đâu

a: =1/5-1/7=2/35

c: =3/5-1/7=21/35-5/35=16/35

\(\dfrac{45}{135}=\dfrac{45:45}{135:45}=\dfrac{1}{3}\)

\(\dfrac{117}{234}=\dfrac{117:117}{234:117}=\dfrac{1}{2}\)

\(\dfrac{1515}{2727}=\dfrac{1515:303}{2727:303}=\dfrac{5}{9}\)

\(\dfrac{232323}{494949}=\dfrac{232323:10101}{494949:10101}=\dfrac{23}{49}\)

\(\left(x-\dfrac{1}{3}\right)+\dfrac{1}{4}=\dfrac{1}{2}\)

\(x-\dfrac{1}{3}=\dfrac{1}{2}-\dfrac{1}{4}\)

\(x-\dfrac{1}{3}=\dfrac{2}{4}-\dfrac{1}{4}\)

\(x-\dfrac{1}{3}=\dfrac{1}{4}\)

\(x=\dfrac{1}{4}+\dfrac{1}{3}\)

\(x=\dfrac{3}{12}+\dfrac{4}{12}\)

\(x=\dfrac{7}{12}\)

\(x-\left(\dfrac{1}{7}+\dfrac{2}{5}\right)=\dfrac{16}{35}\)

\(x-\left(\dfrac{5}{35}+\dfrac{14}{35}\right)=\dfrac{16}{35}\)

\(x-\dfrac{19}{35}=\dfrac{16}{35}\)

\(x=\dfrac{16}{35}+\dfrac{19}{35}\)

\(x=\dfrac{35}{35}\)

\(x=1\)

\(x+\dfrac{3}{7}=\dfrac{2}{5}+\dfrac{3}{10}\)

\(x+\dfrac{3}{7}=\dfrac{4}{10}+\dfrac{3}{10}\)

\(x+\dfrac{3}{7}=\dfrac{7}{10}\)

\(x=\dfrac{7}{10}-\dfrac{3}{7}\)

\(x=\dfrac{49}{70}-\dfrac{30}{70}\)

\(x=\dfrac{19}{30}\)

Ta có: \(\dfrac{21}{35}\)=\(\dfrac{21:7}{35:7}\)=\(\dfrac{3}{5}\)

Vậy \(\dfrac{3}{5}\)+\(\dfrac{5}{4}\)=\(\dfrac{12}{20}\)+\(\dfrac{25}{20}\)=\(\dfrac{37}{20}\)

\(\dfrac{9}{27}\)=\(\dfrac{9:9}{27:9}\)=\(\dfrac{1}{3}\) ; \(\dfrac{15}{20}\)=\(\dfrac{15:5}{20:5}\)=\(\dfrac{3}{4}\)

Vậy \(\dfrac{1}{3}\)+\(\dfrac{3}{4}\)=\(\dfrac{4}{12}\)+\(\dfrac{9}{12}\)=\(\dfrac{13}{12}\)

=4/5+1/5=1

\(\dfrac{4}{5}+\dfrac{3}{15}=\dfrac{4}{5}+\dfrac{3:3}{15:3}=\dfrac{4}{5}+\dfrac{1}{5}=\dfrac{5}{5}=1\)

bằng 1

HT