Question

Rút gọn biểu thức:

(x+y-z)^2+(x-y+z)^2+2*[x^2-(y-z)^2]

Answer 1

Ta có:

(x+y-z)^2 +(x-y+z)^2 + 2[x^2-(y-z)^2]

= (x+y-z)^2 + 2(x-y+z)(x+y-z) + (x-y+z)^2

=(x+y-z+x-y+z)^2

= (2x)^2= 4x^2