Find the product:`(2x-y+3z)(4x^2+y^2+9z^2+2x y+3y z-6x z)`

1.	Find the product:`(2x-y+3z)(4x^2+y^2+9z^2+2x y+3y z-6x z)`
Answer» Putting `2x=a,y=b and, 3z=c`, we get `(2x-y+3z)(4x^2+y^2+9z^2+2xy+3yz-6xz)` `=[2x+(-y)+(3z)]xx[(2x)^2+(-y)^2+(3z)^2-(2x)(-y)-(-y)(3z)-(2x)(3z)]` `=(a+b+c)xx(a^2+b^2+c^2-ab-bc-ca)` `=a^3+b^3+c^3-3abc` `=(2x)^3+(-y)^3+(3z)^3-3xx(2x)xx (-y)xx(3z)` `=8x^-y^3+27z^3+18zyz`.

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