Simplify: `x^7 y^3 z^(-4) xx x^(-4) y^6 z^(-2) xx x^2 z^3`

Simplify: (15x^(5)y^(-2)z^(4))/(5x^(3)y^(-3)z^(2))

Simplify: (x+y-2z)^(2)-x^(2)-y^(2)-3z^(2)+4xy

Simplify (3x^(-2)y^(-3)z^(2)xx5x^(2)xxyxxz^3 )÷x^(3)y^(2)z^(-1)

Simplify (x+y+z)^(3)-(x-y-z)^(2) .

3^4x^3y^6z^4xx27x^(-2)z^(-6)div81xy^(2)z^(-3)= ______

The value of ((a^(x))/(a^(y)))^(x^(2) + xy +y^(2)) xx ((a^(y))/(a^(z)))^(y^(2) + yz + z^(2)) xx ((a^(z))/(a^(x)))^(z^(2) + xz + x^(2)) is