Ob = y + 5 + 2x + x + 2 + 4y = 5y + 3x + 7
[tex]P = \frac{(a+b)*h}{2}[/tex]
[tex]P =\frac{(4y+2x)*(2y-4)}{2} = \frac{8y^{2}-16y+4xy-8x}{2}=4y^{2}-8y+2xy-4x[/tex]
:)
