Bài 2: a: \(A=y^5\left(1+\dfrac{1}{2}-1\right)-2y+5y=\dfrac{1}{2}y^5+3y\)b: \(B=x^2y\left(-\dfrac{1}{7}+\dfrac{1}{7}\right)+x^5y^2\left(1+\dfrac{1}{5}\right)-6xy+1=\dfrac{6}{5}x^5y^2-6xy+1\)c: \(C=x^2y\left(-\dfrac{1}{2}+\dfrac{1}{2}\right)+xy\left(-2-1+1\right)+x\left(-\dfrac{1}{3}+1\right)+\dfrac{1}{2}-\dfrac{1}{4}\)\(=-2xy+\dfrac{2}{3}x+\dfrac{1}{4}\)d: \(D=xy^3\left(-4-\dfrac{1}{3}-2\right)+7x^2y-\dfrac{7}{2}x^3y\)\(=-\dfrac{19}{3}xy^3+7x^2y-\dfrac{7}{2}x^3y\)e: \(E=4x^4-3x^2y^3z^2-2x^3-5x^6+x^3+4x^6\)\(=-x^6+4x^4-x^3-3x^2y^3z^2\)Câu trả lời: Bài 2: a: \(A=y^5\left(1+\dfrac{1}{2}-1\right)-2y+5y=\dfrac{1}{2}y^5+3y\)b: \(B=x^2y\left(-\dfrac{1}{7}+\dfrac{1}{7}\right)+x^5y^2\left(1+\dfrac{1}{5}\right)-6xy+1=\dfrac{6}{5}x^5y^2-6xy+1\)c: \(C=x^2y\left(-\dfrac{1}{2}+\dfrac{1}{2}\right)+xy\left(-2-1+1\right)+x\left(-\dfrac{1}{3}+1\right)+\dfrac{1}{2}-\dfrac{1}{4}\)\(=-2xy+\dfrac{2}{3}x+\dfrac{1}{4}\)d: \(D=xy^3\left(-4-\dfrac{1}{3}-2\right)+7x^2y-\dfrac{7}{2}x^3y\)\(=-\dfrac{19}{3}xy^3+7x^2y-\dfrac{7}{2}x^3y\)e: \(E=4x^4-3x^2y^3z^2-2x^3-5x^6+x^3+4x^6\)\(=-x^6+4x^4-x^3-3x^2y^3z^2\)