A walkway of uniform width is to be built around a square swimming pool with 18-foot edges. How wide should the walkway be to make the area of the walkway’s surface 400 feet?

Given

an 18 ft square with a uniform border of width x

the area of the border is 400 ft²

Find

x

Solution

The outside dimension of the square with the border added is 18+2x, so the total area of square and border is (18+2x)². Subtracting the area of the original square gives the area of the border.

... (18+2x)² -18² = 400

... 4x² +72x = 400 . . . . . simplify

... x² + 18x = 100 . . . . . . .divid by 4

... x² +18x +9² = 100 +9² . . . . complete the square

... (x +9)² = 181 . . . . . . . . .simplify

... x = √181 -9 . . . . . . . . . take the square root, subtract 9

... x ≈ 4.4536 . . . . . . . . . evaluate

The appropriate choice is ...

... c. 4.45 ft

$54.99

step-by-step explanation:

$54.99 includes 500 min. if she does not exceed 500 min then her bill is $54.99

none.

step-by-step explanation:

m

1

=

5

m1=5

b

=

−

1

b=-1

find the slope and y-intercept of the second equation.

tap for more

m

2

=

0

m2=0

b

=

−

6

b=-6

compare the slopes

m

m of the two equations.

m

1

=

5

,

m

2

=

0

m1=5,m2=0

compare the two slopes in the decimal form. if the slopes are equal, then the lines are parallel. if the slopes are not equal, then the lines are not parallel.

m

1

=

5

,

m

2

=

0

m1=5,m2=0