Question

Bài 1: Rút gọn biểu thức

a)(x^2 - 2xy + y^2).(x-y)-(x-y).(x^2 + xy + y^2)

b) 7x.( 4y-x) + 4y.(y-7x)-(4y^2 -7x)

c) (2x+y). (2x+y) +(x-y).(y-z)

Answer 1

giúp mik vs mik k cho

mai mik kt 1 tiết r

Answer 2

a,

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

\(=\left[\left(x^2-2xy+y^2\right)\left(x-y\right)\right]-\left[\left(x-y\right)\left(x^2+xy+y^2\right)\right]\)

\(=\left[\left(x-y\right)^2\left(x-y\right)\right]-\left(x-y\right)^3\)

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

\(=0\)

Answer 3

giúp mik vs please

Answer 4

giúp làm 3 câu a b c đc ko vậy

Answer 5

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

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

\(=\left(x-y\right)\left(-3xy\right)\)