a)A=[\(\dfrac{2}{7}\).(\(\dfrac{1}{4}\)-\(\dfrac{1}{3}\))]:[\(\dfrac{2}{7}\).(\(\dfrac{3}{9}\)-\(\dfrac{2}{5}\))]

A=[\(\dfrac{2}{7}\).(\(\dfrac{1}{4}\)-\(\dfrac{1}{3}\))]:[\(\dfrac{2}{7}\).(\(\dfrac{1}{3}\)-\(\dfrac{2}{5}\))]

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

A=\(\dfrac{-1}{12}\):\(\dfrac{-1}{15}\)

A=\(\dfrac{-1}{12}\).\(\dfrac{-15}{1}\)

A=\(\dfrac{5}{4}\)

b)

a)A=\(\dfrac{3}{5}\).\(\dfrac{6}{7}\)+\(\dfrac{3}{7}\).\(\dfrac{3}{5}\)-\(\dfrac{2}{7}\).\(\dfrac{3}{5}\)

A=\(\dfrac{3}{5}\).(\(\dfrac{6}{7}\)+\(\dfrac{3}{7}\)-\(\dfrac{2}{7}\))

A=\(\dfrac{3}{5}\).1

A=\(\dfrac{3}{5}\)

b)B=(-13.\(\dfrac{2}{5}\)+\(\dfrac{-2}{9}\).\(\dfrac{2}{5}\)+\(\dfrac{2}{5}\).\(\dfrac{11}{9}\)).\(\dfrac{5}{2}\)

B=\(\dfrac{2}{5}\).(-13+\(\dfrac{-2}{9}\)+\(\dfrac{11}{9}\)).\(\dfrac{5}{2}\)

B=\(\dfrac{2}{5}\).(-12).\(\dfrac{5}{2}\)

B=\(\dfrac{-24}{5}\).\(\dfrac{5}{2}\)

B=-12

c)C=(\(\dfrac{-4}{5}\)+\(\dfrac{5}{7}\)).\(\dfrac{3}{2}\)+(\(\dfrac{-1}{5}\)+\(^{\dfrac{2}{7}}\)).\(\dfrac{3}{2}\)

C=(\(\dfrac{-4}{5}\)+\(\dfrac{5}{7}\)+\(\dfrac{-1}{5}\)+\(^{\dfrac{2}{7}}\)).\(\dfrac{3}{2}\)

C=[(\(\dfrac{-4}{5}\)+\(\dfrac{-1}{5}\))+(\(\dfrac{5}{7}\)+\(^{\dfrac{2}{7}}\))].\(\dfrac{3}{2}\)

C=[-1+1].\(\dfrac{3}{2}\)

C=0

d)D=\(\dfrac{4}{9}\):[(\(\dfrac{1}{15}\)-\(\dfrac{2}{3}\))+(\(\dfrac{1}{11}\)-\(\dfrac{5}{22}\))]

D=\(\dfrac{4}{9}\):[\(\dfrac{-3}{5}\)+\(\dfrac{-3}{22}\)]

D=\(\dfrac{4}{9}\).[\(\dfrac{-5}{3}\)+\(\dfrac{-22}{3}\)]

D=\(\dfrac{4}{9}\).-9

D=-4

a)

P=\(\dfrac{2}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{3}{5}\)-\(\dfrac{7}{45}\)+\(\dfrac{5}{9}\)+\(\dfrac{1}{12}\)+\(\dfrac{1}{35}\)

P=(\(\dfrac{2}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{12}\))+(\(\dfrac{5}{9}\)-\(\dfrac{7}{45}\))+\(\dfrac{3}{5}\)+\(\dfrac{1}{35}\)

P=1+\(\dfrac{2}{5}\)+\(\dfrac{3}{5}\)+\(\dfrac{1}{35}\)

P=1+1+\(\dfrac{1}{35}\)

P=2+\(\dfrac{1}{35}\)=\(\dfrac{71}{35}\)

b)

Q=5-\(\dfrac{3}{4}\)+\(\dfrac{1}{5}\)-6-\(\dfrac{7}{4}\)+\(\dfrac{8}{5}\)-2+\(\dfrac{5}{4}\)-\(\dfrac{16}{5}\)

Q=(5-6-2)+(-\(\dfrac{3}{4}\)-\(\dfrac{7}{4}\)+\(\dfrac{5}{4}\))+(\(\dfrac{1}{5}\)+\(\dfrac{8}{5}\)-\(\dfrac{16}{5}\))

Q=-3+(\(\dfrac{-5}{4}\))+(\(\dfrac{-7}{5}\))

Q=\(-\dfrac{113}{20}\)

a) A=(\(\dfrac{1}{3}\)+\(\dfrac{2}{3}\))-(\(\dfrac{8}{15}\)+\(\dfrac{7}{15}\))+(\(\dfrac{-1}{7}\)+1\(\dfrac{1}{7}\))

A=1-1+1

A=1

b)B=\(\dfrac{1}{4}\)+\(\dfrac{3}{5}\)-(\(\dfrac{1}{8}\)-\(\dfrac{2}{5}\)+\(\dfrac{5}{4}\))

B=\(\dfrac{1}{4}\)+\(\dfrac{3}{5}\)-\(\dfrac{1}{8}\)+\(\dfrac{2}{5}\)-\(\dfrac{5}{4}\)

B=(\(\dfrac{1}{4}\)-\(\dfrac{5}{4}\))+(\(\dfrac{3}{5}\)+\(\dfrac{2}{5}\))-\(\dfrac{1}{8}\)

B=(-1)+1-\(\dfrac{1}{8}\)

B=0-\(\dfrac{1}{8}\)

B=-\(\dfrac{1}{8}\)