\(a,\left(4-xy\right)^3\)

\(=4^3-3.4^2xy+3.4.x^2y^2-x^3y^3\)

\(=64-48xy+12x^2y^2-x^3y^3\)

\(b,\left(0,1+xy\right)^3\)

\(=\left(0,1\right)^3+3.\left(0,1\right)^2xy+3.0,1.\left(xy\right)^2+x^3y^3\)

\(=0,001+0,03xy+0,3x^2y^2+x^3y^3\)

\(a,\left(-3x+2\right)^3\)

\(=\left(2-3x\right)^3\)

\(=2^3-3.2^2.3x+3.2.9x^2-27x^3\)

\(=8-36x+54x^2-27x^3\)

\(a,\left(-3x+2\right)^3=\left(2-3x\right)^3=2^3-3.2^2.3x+3.2.9x^2-27x^3=8-36x+54x^2-27x^3\)

\(x^3y^3+125=\left(xy+5\right)\left(x^2y^2-5xy+25\right)\)

a, \(4x^2+4xy+y^2=\left(4x\right)^2+2.2x.y+y^2\)

\(=\left(4x+y\right)^2\)

b, \(9m^2+n^2-6mn=\left(3m\right)^2-2.3m.n+n^2\)

\(=\left(3m-n\right)^2\)

c, \(16a^2+25b^2+40ab=\left(4a\right)^2+2.4a.5b+\left(5b\right)^2\)

\(=\left(4a+5b\right)^2\)

d, \(x^2-x+\dfrac{1}{4}=x^2-2.x.\dfrac{1}{2}+\left(\dfrac{1}{2}\right)^2\)

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

Chúc bạn học tốt!!!

\(2xy^2+x^2y^4+1\\ =\left(xy^2\right)^2+2xy^2.1+1^2\\ =\left(xy^2+1\right)^2\)

Ta có :

\(2xy^2+x^2y^4+1=\left(xy^2\right)^2+2.xy^2.1+1^2\)

\(=\left(xy^2+1\right)^2\)