a.\(=\dfrac{1+4}{5}+\dfrac{5+1+3}{9}=\dfrac{5}{5}+\dfrac{9}{9}=1+1=2\)
b.\(=\dfrac{1+2}{3}+\dfrac{4}{3}+\dfrac{1+5}{6}+\dfrac{2}{6}=1+1+\dfrac{4}{3}+\dfrac{2}{6}=2+\dfrac{4}{3}+\dfrac{2}{6}=\dfrac{10}{3}+\dfrac{2}{6}=\dfrac{11}{3}\)
a
= ( 1/5 + 4/5 ) + ( 5/9 + 1/9 + 3/9)
= 5/5 + 9/9
= 2
b
= ( 1/3 + 4/3 + 2/3) + ( 1/6 + 2/6 + 5/6)
= 7/3 + 8/6
= 22/6 nha bn