So the original area is 300*150 (or 45000 ft^2), but now the new area is (300+3y)(150+3y).
The polynomial in standard form would be 45000+900y+450y+9y^2=45000+1350y+9y^2
But the proper way to write it is 9y^2+1350y+45000
When y=4, we get 9(4^2)+1350(4)+45000=9(16)+54000+45000=144+99000=99144
So the new area would be 99144 ft^2
Hope this helped!
