a)= \(4x^2y+2x^2y-5x^2y-3y^3-5y^3-6xy^2\)

=\(2x^2y-8y^3-6xy\)

b) =\(2xyz-8xyz-11xy^3+2xy^3+4xy-2xy-11\)

=\(-6xyz-9xy^3+2xy-11\)

mình ko viết đề bài đâu 2 câu còn lại làm tương tự nhé

a. \(4x^2y-3y^3-6xy^2-5y^3+2x^2y-5x^2y\)

\(=-8y^3+x^2y-6xy^2\)

b. \(2xyz-11xy^3-8xyz+2xy^3+4xy-11-2xy\)

\(=-6xyz-9xy^3+2xy-11\)

c. \(x\left(x-5\right)-3x\left(x-1\right)+6\left(x-2\right)\)

\(=x^2-5x-3x^2-3x+6x-12\)

\(=-2x^2-2x-12\)

d. \(x^3\left(x-2\right)-2x^2\left(x^2-x\right)+5\left(2x^4-1\right)\)

\(=x^4-2x^3-2x^4-2x^3+10x^4-5\)

\(=9x^4-4x^3-5\)

\(\frac{1}{11xy}\sqrt{\frac{121x^2}{y^6}}=\frac{1}{11xy}.\frac{11x}{y^3}=\frac{1}{y^4}\)

\(Q=7x^2y-2xy+\dfrac{1}{2}x^2y-xy+11xy-\dfrac{1}{3}x+\dfrac{1}{3}+\dfrac{2}{3}x-\dfrac{1}{6}\)

\(Q=\dfrac{15}{2}x^2y+8xy-x-\dfrac{1}{6}\)

Q = ( 7x\(^2\)y + \(\dfrac{1}{2}\)x\(^2\)y ) + ( -2xy - xy + 11xy ) +( -\(\dfrac{1}{3}\)x + \(\dfrac{2}{3}\)x ) + ( -\(\dfrac{1}{3}\) - \(\dfrac{1}{6}\) )

= \(\dfrac{15}{2}\)x\(^2\)y + 8xy + \(\dfrac{1}{3}\)x _ \(\dfrac{1}{2}\)

\(\left(-\dfrac{1}{2}\right)^2\div\dfrac{1}{4}-2\times\left(-\dfrac{1}{2}\right)^2\\= \dfrac{1}{4}\div\dfrac{1}{4}-2\times\dfrac{1}{4}\\ =1-\dfrac{1}{2}\\ =\dfrac{1}{2}\)

\(\left(-2\right)^3\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right)\div\dfrac{5}{12}\)

=  \(-6\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-\dfrac{11}{6}\right)\div\dfrac{5}{12}\)

=  \(\dfrac{1}{4}+-\dfrac{1}{2}\div\dfrac{5}{12}\)

=  \(\dfrac{1}{4}+-\dfrac{6}{5}\)

=  \(\dfrac{1}{4}-\dfrac{6}{5}\)

=  \(-\dfrac{19}{20}\)

\(\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\\ =\dfrac{58}{9}+\dfrac{7}{11}-\dfrac{40}{9}+\dfrac{26}{11}\\ =\dfrac{58}{9}-\dfrac{40}{9}+\dfrac{7}{11}+\dfrac{26}{11}\\ =12+3\\ =15\)

\(a,\left(\dfrac{-1}{2}\right)^2:\dfrac{1}{4}-2\left(-\dfrac{1}{2}\right)^2\)

\(=\left(-\dfrac{1}{2}\right)^2\left(4-2\right)\)

\(=\dfrac{1}{4}.2=\dfrac{1}{2}\)

\(b,\left(-2\right)^3.\dfrac{-1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right):\dfrac{5}{12}\)

\(=\left(-8\right).\dfrac{-1}{24}+\left(-\dfrac{1}{2}\right).\dfrac{12}{5}\)

\(=\dfrac{1}{3}+\left(-\dfrac{1}{5}\right)=\dfrac{2}{15}\)

\(c,\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\)

\(=\dfrac{701}{99}-\dfrac{206}{99}=\dfrac{495}{99}=5\)

\(d,10\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+\dfrac{3}{15\%}\)

\(=\dfrac{51}{5}-30+20=\dfrac{1}{5}\)

\(e,\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}\)

\(=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}.\left(-\dfrac{7}{11}\right)\)

\(=-\dfrac{5}{11}\)

\(f,\dfrac{-5}{7}.\dfrac{2}{11}+\left(-\dfrac{5}{7}\right).\dfrac{9}{11}+1\dfrac{5}{7}\)

\(=\left(-\dfrac{5}{7}\right)\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\)

\(=\left(-\dfrac{5}{7}\right)+\dfrac{12}{7}=1\)

\(4.3^{x-1}+2.3^{x+2}=4.3^6+2.3^9\)

\(3^{x-1}.\left(4+2.3^3\right)=3^6.\left(4+2.3^3\right)\)

\(\Leftrightarrow3^{x-1}=3^6\)

\(\Leftrightarrow x-1=6\)

\(\Leftrightarrow x=7\)

Vậy \(x=7\)

hai bài mà bn ??

a: \(=\dfrac{-3-5-7}{4}=\dfrac{-15}{4}\)

b: \(=\dfrac{-6-5-2+6}{11}=\dfrac{-7}{11}\)