A rectangular area is to be enclosed using an existing wall as one side 100m of fencing are available for the

three side. It is desire to make the areas as large as

possible. Find the necessary dimension of the

enclosure and the maximum area.​

Step-by-step explanation:

Let the one of the side lengths of the rectangle be and the other be .

We can write the following equations, where will be the side opposite to the wall:

From the first equation, we can isolate and substitute into the second equation:

Therefore, the parabola denotes the area of this rectangular enclosure. The maximum area possible will occur at the vertex of this parabola.

The x-coordinate of the vertex of a parabola in standard form is given by .

Therefore, the vertex is:

Plug in to the equation to get the y-coordinate:

Thus the vertex of the parabola is at . This tells us the following:

And therefore, the desired answers are:

the answer is b.

step-by-step explanation:

identity property is where 0+whatever number=whatever number. basically 0+ a number.

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