`=zgeqy=8/7y^2 1/3z^2`

Simplify: 2-3z^(2)+5yz+7y^(2)-8+z^(2)-6yz-9y^(2)+1-2z^(2)-2yz-y^(2)

Find x,y,z using Cramer's Rule,if 5/x-7/y+1/z=11,6/x-8/y-1/z=15,3/x+2/y-6/z=7.

If x prop y and y prop z , then prove that (x^7+y^7 +z^7) prop (x^5y^2 +x^3z^4 +y^5z^2)

and "Delta"_2=x y^2z^3x^4y^5z^6x^7y^8z^9 Then "Delta"_1"Delta"_2 is equal to "Delta"2 3 b. "Delta"2 2 c. "Delta"2 4 d. none of these