Answer:
2x^2 + 100x +800
1350 ft^2
Step-by-step explanation:
The length of the pool and walkway is x+40
The width of the pool and walkway is x +20+x = 2x+20
Area is length times width
A = (x+40) *(2x+20)
We can FOIL to find the area
first x*2x = 2x^2
outer x*20 =20x
inner 2x*40 = 80x
last = 40*20 = 800
Add these together
2x^2 +20x+80x+800
2x^2+100x+800
b. x=5
2x^2 + 100x +800
2(5)^2 +100(5) +80
2*25 +500+800
50+1300
1350 ft^2
