Question

Viết các biểu thức sau dưới dạng tổng:

a)\(\left(x+y+z\right)^2\)

b)\(\left(x-y+z\right)^2\)

c)\(\left(x-y-z\right)^2\)

Answer 1

\(a.\left(x+y+z\right)^2=x^2+y^2+z^2+2xy+2yz+2xz\\ b.\left(x-y+z\right)^2=x^2+y^2+z^2-2xy-2yz+2xz\\ c.\left(x-y-z\right)^2=x^2+y^2+z^2-2xy+2yz-2xz\)

Answer 2

a, \(\left(x+y+z\right)^2=x^2+y^2+c^2+2xy+2yz+2zx\)

b, \(\left(x-y-z\right)^2=x^2+y^2+z^2-2xy+2yz-2zx\)

c, \(\left(x-y+z\right)^2=x^2+y^2+z^2-2xy-2yz+2xz\)