Question

Tính nhanh

A= ( 38 x 333 - 111 x 133 ) x 2018

B = ( 25 + 3 x 75 - 125 x 2 ) : 20182019

C = ( 244 x 395 - 244 x 195 ) : ( 122 x 200 )

D = ( 355 x 45 x 55 ) : ( 11 x 9 x 7)

E = 1 x 2 + 2 x 3 + 3 x 4 + 4 x 5 + ... + 49 x 50

Answer 1

a: \(A=\left[111\cdot\left(38\cdot3-133\right)\right]\cdot2018\)

\(=111\cdot\left(-19\right)\cdot2018=-4255962\)

b: \(B=\left[25\left(1+3\cdot3-5\cdot2\right)\right]:20182019\)

\(=25\left(1+9-10\right):20182019=0\)

c: \(C=\dfrac{\left[244\left(395-195\right)\right]}{122\cdot200}=\dfrac{244}{122}=2\)

d: \(D=\dfrac{355\cdot45\cdot55}{11\cdot9\cdot7}=\dfrac{355\cdot5\cdot5}{7}=\dfrac{8875}{7}\)