Question

Giúp mình bài 3 với ạ.mình cảm ơn

Answer 1

a: \(E=x^4z^3y\left(\dfrac{2}{5}-0+1\right)=\dfrac{7}{5}x^4yz^3\)

b: \(E=\dfrac{7}{5}x^4yz^3=\dfrac{7}{5}\cdot2^4\cdot\dfrac{1}{2}\cdot\left(-1\right)^3=\dfrac{7}{5}\cdot8\cdot\left(-1\right)=-\dfrac{56}{5}\)

Answer 2

a, \(=\left(\dfrac{2}{5}+1\right)x^4z^3y=\dfrac{7}{5}x^4z^3y\)

b, Thay x = 2 ; y = 1/2 ; z = -1 vào ta được 

\(\dfrac{7}{5}.16.\dfrac{-1}{2}.1=-\dfrac{56}{5}\)