First, draw a picture. I'm going to try to do this on here... we'll see how it goes.
So, we have a triangle with sides x, 2x+6, and 2x+4. From there, you can use the Pythagorean theorem to solve...
Are you trying to expand this? If so, FOIL it. First, Outside, Inside, Last.
FIRST - x^2
OUTSIDE - -15
INSIDE - -3x
LAST - 5x
Add them all up - x^2 -3x+5x-15, and then simplify to x^2+2x-15.
To graph this, do a T-table. That's the easiest way. Do a T-table with several values, and based on that, you can determine if it is growth or decay.
PEMDAS - parentheses, exponents, multiplication/division, addition/subtraction.
3+6+4 = 13
A = 252 sq. ft = l*w
2l + 2w = 66, 2(l+w) = 66, so l+w = 33
w = 252/l
l+(252/l) = 33
l^2 + 252 = 33l
l^2 - 33l - 252 = 0
You're at a quadriatic equation, which you can solve. You will get two answers - toss out the unreasonable one (hint - negative answer,...