Question

( 3x + 4y + 5z ) ( 2x + 3y + 4z)

Answer 1

   solution

(3x+4y+5z)(2x+3y+4z)

(6x²+9xy+12xz+8xy+16yz+10xz+15zy+20z²)

6x²+17xy+22xz+31yz+20z²

⇒(3x+4y+5z)(2x+3y+4z)=6x²+17xy+22xz+31yz+20z²

Answer 2

3x(2x + 3y + 4z) +4y(2x + 3y + 4z) +5z(2x + 3y + 4z)

=> 6x^2 + 9xy + 12xz + 8xy + 12y^2 + 16yz + 10xz + 15yz + 20z^2

= 6x^2 + 17xy + 22xz + 12y^2 + 31yz + 20z^2