a)73.(74-72)+72.(73-74)

=74.(73-73)+(72-72)

=74.0+0

=74

b)37.(25+27)-27.(37+25)

=37.52-27.62

=1924-1674

=250

tick cho mk nha bạn

a) \(C=\frac{3}{4.7}+\frac{3}{7.10}+\frac{3}{10.13}+...+\frac{3}{73.76}\)

\(C=1.\left(\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+\frac{1}{10}-\frac{1}{13}+...+\frac{1}{73}-\frac{1}{76}\right)\)

\(C=1.\left(\frac{1}{4}-\frac{1}{76}\right)\)

\(C=1.\frac{9}{38}\)

\(C=\frac{9}{38}\)

b) \(D=\frac{5}{10.11}+\frac{5}{11.12}+\frac{5}{12.13}+...+\frac{5}{99.100}\)

\(D=5.\left(\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}+\frac{1}{12}-\frac{1}{13}+...+\frac{1}{99}+\frac{1}{100}\right)\)

\(D=5.\left(\frac{1}{10}-\frac{1}{100}\right)\)

\(D=5.\frac{9}{100}\)

\(D=\frac{99}{20}\)

Giúp mình nha 

Ra số nhiều nắm bạn ạ!

\(\frac{46}{100}+\frac{19}{42}+\frac{60}{74}+\frac{23}{42}+\frac{14}{72}\)

\(=\frac{23}{50}+\frac{19}{42}+\frac{30}{37}+\frac{23}{42}+\frac{7}{36}\)

\(=\left(\frac{23}{50}+\frac{30}{37}+\frac{7}{36}\right)+\left(\frac{19}{42}+\frac{23}{42}\right)\)

\(=2,465255...\)

\(P=\dfrac{3^{140}\cdot2^{74}-2^4}{3^{72}\cdot3^{70}\cdot2^{70}-3^2}=\dfrac{2^4\left(3^{140}\cdot2^{70}-1\right)}{3^2\left(3^{140}\cdot2^{70}-1\right)}=\dfrac{16}{9}\)