Question 823564
---
perimeter = 2x + 2y = 9
area = xy
---
2x + 2y = 9
a = xy
---
2y = 9 - 2x
y = (9 - 2x)/2
a = x(9 - 2x)/2
---
a = (9/2)x - xx
a = -xx + (9/2)x
a = -xx + 4.5x
---
the above quadratic equation is in standard form, with a=-1, b=4.5, and c=0
---
to solve the quadratic equation, by using the quadratic formula, copy and paste this:
-1 4.5 0
into this solver: https://sooeet.com/math/quadratic-equation-solver.php
---
the quadratic vertex is a maximum at: ( x= 2.25, a= 5.0625 )
---
answer:
the frame area is maximum at 5.0625 sq.ft when the frame dimensions are: 
L= 2.25 ft
W= 2.25 ft
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php