Bài 1 :
a ) \(x^6-4=\left(x^3\right)^2-2^2=\left(x^3-2\right)\left(x^3+2\right)\)
b ) \(-9x^2+1=1-\left(3x\right)^2=\left(1-3x\right)\left(1+3x\right)\)
c ) \(x^{10}-9=\left(x^5\right)^2-3^2=\left(x^5-3\right)\left(x^5+3\right)\)
Bài 2 :
a ) \(x^2+10x+26+y^2+2y\)
\(=x^2+10x+25+y^2+2y+1\)
\(=\left(x+5\right)^2+\left(y+1\right)^2\)
b ) \(x^2-2xy+2y^2+2y+1\)
\(=\left(x^2-2xy+y^2\right)+\left(y^2+2y+1\right)\)
\(=\left(x-y\right)^2+\left(y+1\right)^2\)
c ) \(a^2-6a+10a+b^2+4b\)
\(=a^2+4a+b^2+4b\)
\(=a^2+4a+4+b^2+4b+4-8\)
\(=\left(a+2\right)^2+\left(b+2\right)^2-8\)
d ) \(4x^2+2y^2-4xy-2y+1\)
\(=\left(2x\right)^2-4xy+y^2+y^2-2y+1\)
\(=\left(2x-y\right)^2+\left(y-1\right)^2\)
