a/ Có sai đề hăm ta ?
b/ \(x^2-\left(a+b\right)x+ab\)
\(=x^2-ax-bx+ab\)
\(=x\left(x-a\right)-b\left(x-a\right)\)
\(=\left(x-a\right)\left(x-b\right)\)
c/ \(x^2y+xy^2-x-y\)
\(=\left(x^2y-x\right)+\left(xy^2-y\right)\)
\(=x\left(xy-1\right)+y\left(xy-1\right)\)
\(=\left(xy-1\right)\left(x+y\right)\)
a/\(x^2y+xy+x+1=xy\left(x+1\right)+\left(x+1\right)=\left(x+1\right)\left(xy+1\right)\)
b/\(x^2-\left(a+b\right)x+ab=x^2-ax-bx+ab=x\left(x-a\right)-b\left(x-a\right)=\left(x-a\right)\left(x-b\right)\)
c/
\(x^2y+xy^2-x-y=xy\left(x+y\right)-1\left(x+y\right)=\left(x+y\right)\left(xy-1\right)\)
Làm lại cả 3 câu cho bạn nhé
a/
b\(x^2-\left(a+b\right)x+ab=x^2-ax-bx+ab=x\left(x-a\right)-b\left(x-a\right)=\left(x-a\right)\left(x-b\right)\)c/
\(x^2y+xy^2-x-y=xy\left(x+y\right)-1\left(x+y\right)=\left(x+y\right)\left(xy-1\right)\)
a/ \(x^2y+xy+x+1\)
\(=\left(x^2y+x\right)+\left(xy+1\right)\)
\(=x\left(xy+1\right)+\left(xy+1\right)\)
\(=\left(xy+1\right)\left(x+1\right)\)
