\(a,\dfrac{3}{10}+\dfrac{15}{4}:5=\dfrac{3}{10}+\dfrac{15}{4}\times\dfrac{1}{5}=\dfrac{3}{10}+\dfrac{3}{4}=\dfrac{6}{20}+\dfrac{15}{20}=\dfrac{21}{20}\\ b,\dfrac{6}{7}\times3-\dfrac{2}{3}\times3=\left(\dfrac{6}{7}-\dfrac{2}{3}\right)\times3=\left(\dfrac{18}{21}-\dfrac{14}{21}\right)\times3=\dfrac{4}{21}\times3=\dfrac{4}{7}\)
a) 3/10+3/4
= 6/2+ 15/20
= 21/20
b) (6/7-2/3)x3
= 4/21x3
= 12/21
= 4/7
\(a,=\dfrac{3}{10}+\dfrac{3}{4}=\dfrac{21}{20}\)
\(b,=3\times\left(\dfrac{6}{7}-\dfrac{2}{3}\right)=3\times\dfrac{4}{21}=\dfrac{4}{7}\)
a. \(\dfrac{3}{10}\)+\(\dfrac{15}{20}\)=\(\dfrac{6}{20}\)+\(\dfrac{15}{20}\)=\(\dfrac{21}{20}\)
b.(\(\dfrac{6}{7}\)-\(\dfrac{2}{3}\))x3=\(\dfrac{4}{21}\)x3=\(\dfrac{4}{7}\)
