# Math Help - Quadratic models

1. ## Quadratic models

2. if the width is $x$, then the length can be written as $l = 60 - 2x$

and so, $A = x(60 - 2x) = 60x - 2x^2$

for the third question:
solve for first derivative of $A$ and equate it to $0$ and solve for the value of $x$.. after solving for $x$, substitute it to the $A$ above..