Answer:
[tex]Area\ of\ walkway=4x^2+56x\ meter^2[/tex]
Step-by-step explanation:
[tex]Length\ of\ garden=16\ meters\\\\Width\ of\ garden=12\ meters\\\\Width\ of\ walkway=x\ meters\\\\Now\ Length\ of\ new\ rectangular=16+x+x\ \ \ \ \ (as\ x\ meter\ walkway\ increased\ both\ the\ sides)\\\\Now\ width\ of\ new\ rectangular=12+x+x\ \ \ \ \ (as\ x\ meter\ walkway\ increased\ both\ the\ sides)\\\\Area\ of\ walkway=Area\ of\ new\ rectangular-Area\ of\ rectangular\\\\Area\ of\ rectangle=length\times width\\\\Area\ of\ walkway=(16+2x)\times (12+2x)-16\times 12[/tex][tex]Area\ of\ walkway=16\times 12+2x\times 12+16\times 2x+2x\times 2x-16\times 12\\\\Area\ of\ walkway=4x^2+56x\ meter^2[/tex]
