Arectangular swimming pool has a length of l yards and a width 5 yards less than its length. how much does it cost to border the outside
of the pool using 1-yard square tiles that cost $4 each?
a) (16l- 40) dollars
b) (16l - 24) dollars
c) (4l - 6) dollars
d) (16l - 20) dollars

A) (16L- 40) dollars

Step-by-step explanation:

Given in the question that the dimensions of the pool are;

Length= L yards

Width= L-5 yards

Finding the perimeter of the pool

P=2(l+w) where l is length and w is width

P=2(L+L-5)

P=2(2L-5)

P=4L-10

The cost for 1 yard square tile is $4

The border will cost ;

$4(4l-10)

$ (16 l-40)

Step-by-step explanation:

Givens

According to the given statements, length and width are related with

Then, we need to find the perimeter expression.  Remember that the perimeter is the sum of all sides

We know that each tile cost $4, and they cover all the perimeter. So, we multiply to find the total cost

That is, the total cost is (16L - 40) dollars.

Therefore, the right answer is A.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

y = 2x

step-by-step explanation:

if you divide each number in the sequence, you'll see that they all have a multiple factor of 2. each number in the series, and any other numbers which may continue, will be multiplied by 2. therefore, y is the next number in the sequence, and x is the current one, so, our formula will be y = 2x.