Question

Answer 1

a: M=2x^2(2x^2-3x+1)

=2x^2*2x^2-2x^2*3x+2x^2*1

=4x^4-6x^3+2x^2

b: N=(-1/2x)(2x^2-3x+4)

\(=-\dfrac{1}{2}x\cdot2x^2+\dfrac{1}{2}x\cdot3x-\dfrac{1}{2}x\cdot4\)

\(=-x^3+\dfrac{3}{2}x^2-2x\)

c: \(P=\dfrac{1}{2}xy\left(-x^3+2xy-4y^2\right)\)

\(=-\dfrac{1}{2}x^3\cdot xy+\dfrac{1}{2}xy\cdot2xy-\dfrac{1}{2}xy\cdot4y^2\)

\(=-\dfrac{1}{2}x^4y+x^2y^2-2xy^3\)

d: \(\dfrac{1}{2}x^2y\left(2x^3-\dfrac{2}{5}xy^2-1\right)\)

\(=\dfrac{1}{2}x^2y\cdot2x^3-\dfrac{1}{2}x^2y\cdot\dfrac{2}{5}xy^2-\dfrac{1}{2}x^2y\cdot1\)

\(=x^5y-\dfrac{1}{5}x^3y^3-\dfrac{1}{2}x^2y\)