Acircular pool with a diameter of 18 ft will have a uniform 4 ft concrete walkway poured around it. if the concrete cost $4.25 a square foot of surface area, approximately how much will it cost for the concrete? a. $1,174.70 b. $276.40 c. $1,714.07 d. $1,247.08

Answer : $1,174.70

A circular pool has  diameter of 18 ft will have a uniform 4 ft concrete walkway   around it.

Diameter = 18ft . So radius =

Area of circular pool =

Radius of the pool with concrete = 9 + 4= 13

Area of circular pool with concrete=  

Now surface area of concrete = area of pool with concrete - area of pool

Surface area = 530.66 - 254.34 = 276.32 square feet

the concrete cost $4.25 a square foot of surface area

So the cost for the concrete =  276.32 * 4.25 = $ 1174.36

We used the approximate value of pi that is 3.14 . so we got approximate answer

The option close to our answer is $1,174.70

$1,174.70 is the cost for the concrete

the formula of a slope:

from a table we have

substitute:

the slope of f(x) is -1.

the graph of funcfion g(x) is a horizontal line. the slope of a horizontal line is equal 0. therefore the slope of g(x) is 0.

-1 < 0