Question

[bui pham phuong Uyen]

Rut gon bieu thuc

a)x(x-y)+y(x-y)

b)\(^{x^{n-1}}\)(x+y)-y(\(x^{n-1}\) +\(y^{n-1}\))

Answer 1

[Đức Hiếu]

a, \(x\left(x-y\right)+y\left(x-y\right)=x^2-xy+xy-y^2\)

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

b, \(x^{n-1}\left(x+y\right)-y\left(x^{n-1}+y^{n-1}\right)\)

\(=x^n+x^{n-1}y-\left(x^{n-1}y+y^n\right)\)

\(=x^n+x^{n-1}y-x^{n-1}y-y^n=x^n-y^n\)

Chúc bạn học tốt!!!

Answer 2

[tuyền thanh]

a, x(x-y)+y(x-y)=(x-y)(x+y)

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

b, \(x^{n-1}\left(x+y\right)-y\left(x^{n-1}+y^{n-1}\right)=x^{n-1+1}+xy^{n-1}-xy^{n-1}-y^{n-1+1}\)

=x\(^{x^n+xy^{n-1}-xy^{n-1}-y^n}\)

=\(x^n-y^n\)

tl muộn nhưng dễ hiểu hơn câu tl trc