Question

Tính:

B = [-2008. 57 + 1004. (-86) : [32. 74] + 16. (-48)

C = 75. (2 - 128) - 128. (-75)

D = \(\left(1.\dfrac{1}{2}\right).\left(1.\dfrac{1}{3}\right).\left(1.\dfrac{1}{4}\right)...\left(1.\dfrac{1}{2018}\right)\)

E = \(\dfrac{1}{4.9}+\dfrac{1}{9.14}+\dfrac{1}{14.19}+\dfrac{1}{64.69}+\dfrac{1}{69}.74\)

Answer 1

b: \(C=75\left(2-128+128\right)=75\cdot2=150\)

e: \(E=\dfrac{1}{5}\left(\dfrac{5}{4\cdot9}+\dfrac{5}{9\cdot14}+...+\dfrac{5}{69\cdot74}\right)\)

\(=\dfrac{1}{5}\left(\dfrac{1}{4}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{14}+...+\dfrac{1}{69}-\dfrac{1}{74}\right)\)

\(=\dfrac{1}{5}\cdot\dfrac{70}{74}=\dfrac{14}{74}=\dfrac{7}{37}\)