Answer:

Perimeter of rectangle =2(l+b)

=2[(5x²+16y²+12z²+7)+(12x²-4y²+9z²+15)]

=2[(5x²+12x²)+(16y²-4y²)+(12z²+9z²)+(7+15)]

=2(17x²+12y²+21z²+22)

=34x²+24y²+42z²+44

Step-by-step explanation:

Perimeter=2((5x2−3y2)+(x2+2xy))

                =2(6x2−3y2+2xy)

                =12x2−6y2+4xy

∴Perimeter=12x2−6y2+4xy