Question

1. Thực hiện phép tính

a. \(\left(-2xy^2z^3\right)^3\). \(\left(\dfrac{5}{2}xy^3\right)^2\). \(\left(\dfrac{-4}{125}xy\right)\)

b. \(2^1_3x^2y^5-3^2_5x^3y-1^1_2x^2y^5+2^2_3x^3y\)

Answer 1

a, \(\left(-2xy^2z^3\right)^3.\left(\dfrac{5}{2}xy^3\right)^2.\left(\dfrac{-4}{125}xy\right)\)

\(=\left(-2\right)^3.x^3.\left(y^2\right)^3.z^3.\left(\dfrac{5}{2}\right)^2.x^2.\left(y^3\right)^2.\dfrac{-4}{125}.x.y\)

\(=\left(-2\right)^3.\left(\dfrac{5}{2}\right)^2.\dfrac{-4}{125}.\left(x^3.x^2.x\right).\left(y^6.y^6.y\right).z^3\)

\(=\left(-8\right).\dfrac{25}{4}.\dfrac{-4}{125}.x^6.y^{13}.z^3\)

\(=1,6.x^6.y^{13}.z^3\)

Answer 2

a, \(\left(-2xy^2z^3\right).\left(\dfrac{5}{2}xy^3\right)^2.\left(\dfrac{-4}{125}xy\right)\)

= \(\left(-5x^2y^5z^3\right)^5.\left(\dfrac{-4}{125}xy\right)\)

= \(\left(\dfrac{4}{25}x^3y^6z^3\right)^5\)

b, \(2\dfrac{1}{3}x^2y^5-3\dfrac{2}{5}x^3y-1\dfrac{1}{2}x^2y^5+2\dfrac{2}{3}x^3y\)

= \(\dfrac{7}{3}x^2y^5-\dfrac{17}{5}x^3y-\dfrac{3}{2}x^2y^5+\dfrac{8}{3}x^3y\)

= \(\dfrac{5}{6}x^2y^5-\dfrac{11}{15}x^3y\)