a, \(\left(x+y\right)^2-y^2=\left(x+y-y\right)\left(x+y+y\right)=x\left(x+2y\right)\left(đpcm\right)\)
b,\(\left(x^2+y^2\right)-\left(2xy\right)^2=\left(x^2+2xy+y^2\right)\left(x^2-2xy+y^2\right)=\left(x+y\right)^2\left(x-y\right)^2\left(dpdcm\right)\)
a) Có (x+y)2-y2=x2+2xy+y2-y2=x2+2xy=x(x+2y)
Vậy (x+y)2-y2=x(x+2y)
câu b mmik sai đề sory mn chữa lại giúp mik ak
b)(x2+y2)2-(2xy)2=(x+y)2(x-y)2