[tex]P=\frac{h(a+b)}{2} =\frac{6(x+2x)}{2} =\frac{18x}{2} =9x=9*9=81[j^{2}]\\\\Ob=2(x-1.5)+x+2x=2x-3+3x=5x-3=5*9-3=42[/tex]
