What is the area of the pool with the walkway? Without the walkway? What happens if you subtract these two areas?
About 3.6ft.
Practice makes perfect
We are given a pool measuring 25ft by 10ft and we want to add a walkway around it. Let w be the width of the walkway.
To find the area of the walkway, we subtract the area of just the pool from the area of the pool with the walkway.
A_(walkway) &= (25+2w)(10+2w) - 25* 10Let's simplify the expression above.
The height of the walkway is 1ft. This implies that the volume of cement needed to add the walkway is V = (4w^2+70w)1=4w^2+70w ft^3. Since we have only 304ft^3 of cement, we need to set the equation below.
304 = 4w^2+70w
Let's solve the equation for x.
From the final equation, we obtain two solutions: one using the positive sign and another with the negative sign.
w_(1,2) = -35± 49.407/4
w_1 = -35 + 49.407/4
w_2 = -35 - 49.407/4
w_1 = 3.6
w_2 = -21.1
Since w represents the width of the walkway it cannot be negative, so we disregard the negative option. In conclusion, the width of the walkway is about 3.6ft.
