Question

1/2 + 1/3 - 1/5 

1/5 : 4 +3/4

4/3 \(\times\) 9/5 -3/10

15/14 : 10/21 \(\times\) 1/5

Answer 1

\(\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{5}=\dfrac{15}{30}+\dfrac{10}{30}-\dfrac{12}{30}=\dfrac{3}{30}=\dfrac{1}{10}\)

\(\dfrac{1}{5}:4+\dfrac{3}{4}=\dfrac{1}{5}\times\dfrac{1}{4}+\dfrac{3}{4}=\dfrac{1}{20}+\dfrac{3}{4}=\dfrac{1}{20}+\dfrac{15}{20}=\dfrac{16}{20}=\dfrac{4}{5}\)

\(\dfrac{4}{3}\times\dfrac{9}{5}-\dfrac{3}{10}=\dfrac{36}{15}-\dfrac{3}{10}=\dfrac{13}{5}-\dfrac{3}{10}=\dfrac{26}{10}-\dfrac{3}{10}=\dfrac{23}{10}\)

\(\dfrac{15}{14}:\dfrac{10}{21}\times\dfrac{1}{5}=\dfrac{15}{14}\times\dfrac{21}{10}\times\dfrac{1}{5}=\dfrac{315}{140}\times\dfrac{1}{5}=\dfrac{9}{4}\times\dfrac{1}{5}=\dfrac{9}{20}\)

Answer 2

a: =5/6-1/5

=25/30-6/30=19/30

b: =1/20+3/4

=1/20+15/20=16/20=4/5

c: =36/15-3/10

=72/30-9/30=63/30=2,1