Đặt 3759=a; 5741=b

Theo đề, ta có: \(E=4\dfrac{7}{b}\cdot\dfrac{1}{a}-\dfrac{4}{a}\cdot\left(1+\dfrac{2}{b}\right)+\dfrac{1}{a}+\dfrac{1}{ab}\)

\(=\dfrac{4b+7}{b}\cdot\dfrac{1}{a}-\dfrac{4}{a}\cdot\dfrac{b+2}{b}+\dfrac{b+1}{ab}\)

\(=\dfrac{4b+7-4b-8+b+1}{ab}=\dfrac{b}{ab}=\dfrac{1}{a}=\dfrac{1}{3759}\)

\(xy\left(x-y\right)+yz\left(y-z\right)+xz\left(z-x\right)\\ =xy\left(x-y\right)+yz\left[-\left(x-y\right)-\left(z-x\right)\right]+xz\left(z-x\right)\\ =xy\left(x-y\right)-yz\left(x-y\right)-yz\left(z-x\right)+xz\left(z-x\right)\\ =\left(x-y\right)\left(xy-yz\right)+\left(z-x\right)\left(xz-yz\right)\\ =y\left(x-y\right)\left(x-z\right)+z\left(z-x\right)\left(x-y\right)\\ =\left(x-y\right)\left(x-z\right)\left(y-z\right)\)

(4568 + 3759) - (4563 + 3759)

= 4568 + 3759 - 4563 - 3759

= 3

Làm lại 

(4568 + 3759) - (4568 + 3759)

= 4568 + 3759 - 4563 + 3759

= 5

Lộn nữa

(4568 + 3759) - (4563 + 3759)

= 4568 + 3759 - 4563 + 3759

= 5

63740 + 3759 = 67499

tính thuận tiện nhất :
3759 - 642 - 117

= 3759 - ( 642 - 117 )

= 3759 - 525

= 3234.

= 3759 - ( 642 - 117 )

= 3759 - 525

= 3234

= 3759 - ( 642 - 117 )

= 3759 - 525

= 3234