Rút gọn:
1. (xy)2 \(-\frac{1}{2}\)x2y2 + 3xy2. (\(-\frac{1}{3}\)x)
2. 4. (\(-\frac{1}{2}\)x)2\(-\frac{3}{2}\)x.(-x) + \(\frac{1}{3}\)x2
3. -4. (2x)2y3 + \(\frac{1}{2}\)xy. (-2xy2) + \(\frac{1}{4}\)x2y3
4. \(\frac{1}{3}\)x4y\(-\frac{5}{3}\)x3. (\(\frac{5}{2}\)xy) +\(\frac{3}{4}\)x4y
5. (-2x3y4)2 - 5x2y. (\(\frac{3}{4}\)x4y7)\(-\frac{2}{3}\)x6y8
1, \(\left(xy\right)^2-\frac{1}{2}x^2y^2+3xy^2.\left(-\frac{1}{3}x\right)\)
\(=x^2y^2-\frac{1}{2}x^2y^2-x^2y^2\)
\(=-\frac{1}{2}x^2y^2\)
2, \(4.\left(-\frac{1}{2}x\right)^2-\frac{3}{2}x.\left(-x\right)+\frac{1}{3}x^2\)
\(=x^2+\frac{3}{2}x^2+\frac{1}{3}x^2\)
\(=\frac{17}{6}x^2\)
3, \(-4.\left(2x\right)^2y^3+\frac{1}{2}xy.\left(-2xy^2\right)+\frac{1}{4}x^2y^3\)
\(=-16x^2y^3-x^2y^3+\frac{1}{4}x^2y^3\)
\(=-\frac{67}{4}x^2y^3\)
4, \(\frac{1}{3}x^4y-\frac{5}{3}x^3.\left(\frac{5}{2}xy\right)+\frac{3}{4}x^4y\)
\(=\frac{1}{3}x^4y-\frac{25}{6}x^4y+\frac{3}{5}x^4y\)
\(=-\frac{97}{30}x^4y\)
5, \(\left(-2x^3y^4\right)^2-5x^2y.\left(\frac{3}{4}x^4y^7\right)-\frac{2}{3}x^6y^8\)
\(=4x^6y^8-\frac{15}{4}x^6y^8-\frac{2}{3}x^6y^8\)
\(=-\frac{5}{12}x^6y^8\)
