Six rectangles have a area of 64 square units what is the perimeter

Solution:1.A= 64m^2, l = 12 mA = wl Solving for PP=2 l+2(A/ l) = 2·12+2·64/12 ≈ 34.66667 m
Solution:2.A= 64m^2, l = 4 mA = wl Solving for PP=2 l+2 (A/ l) = 2·4+2·64/4 ≈ 40 m
Solution:3.A= 64m^2, l = 24 mA = w l Solving for PP=2 l+2 (A/ l) = 2·24+2·64/24 ≈ 53.33333 m
Solution:4.A= 64m^2, l = 16 mA = w l Solving for PP=2 l+2 (A/ l) = 2·16+2·64/16 ≈ 40 m Solution:5.A= 64m^2, l = 8 mA = w l Solving for PP=2 l+2 (A/ l) = 2·8+2·64/8 ≈ 32 m 
Solution:6.A= 64m^2, l = 32 mA = w l Solving for PP=2 l+2 (A/ l) = 2·32+2·64/32 ≈ 68 m

First subtract 10 from both side
y^2+6y-16=0
(y+8)(y-2)=0
-8 and 2