the area of a rectangle is 425 square feet. if the perimeter is 84 feet, find the length and the width of the rectangle

User Icon for Henry Henry answered
13 years ago

Eq1: L*W = 425Ft^2.

Eq2: 2L + 2W = 84Ft.

L + W = 42.
L e 42-W,

In Eq1, substitute 42-W for L:
(42-W)W = 425,
42W - W^2 - 425 = 0,
W^2 -42W + 425 = o,
(W-25)(W-17) = 0,

W-25 = 0,
W = 25.

W-17 = 0,
W = 17.

In Eq1 substitute 17 for W:
L*17 = 425,
L = 25 Ft., W = 17.

When L = 17, W = 25.

User Icon for Explain Bot Explain Bot answered
11 months ago

To find the length and width of the rectangle when given the area and perimeter, we can use a system of equations.

Let's assume that the length of the rectangle is L and the width is W.

We know that the area of a rectangle is given by the formula: Area = Length * Width

In this case, the area of the rectangle is given as 425 square feet, so we can write the equation as:
L * W = 425 ----(Equation 1)

We also know that the perimeter of the rectangle is given by the formula: Perimeter = 2 * (Length + Width)

In this case, the perimeter is given as 84 feet, so we can write the equation as:
2 * (L + W) = 84 ----(Equation 2)

Now, we have a system of equations with two variables (L and W). We can solve this system to find the values of L and W that satisfy both equations.

To solve the system, we can use substitution or elimination method. Let's use substitution method:

From Equation 1, we can solve for L in terms of W:
L = 425 / W

Now, substitute this value of L into Equation 2:
2 * (425 / W + W) = 84

Simplify the equation:
2 * (425 + W^2) / W = 84

Multiply both sides of the equation by W to eliminate the denominator:
2 * (425 + W^2) = 84 * W

Expand and rearrange the equation:
850 + 2W^2 = 84W

Rearrange the equation in standard quadratic form:
2W^2 - 84W + 850 = 0

Now, we can solve this quadratic equation for W.

You can use the quadratic formula: W = (-b +/- sqrt(b^2 - 4ac)) / 2a

In this case, a = 2, b = -84, and c = 850.

Substitute these values in the quadratic formula to find the values of W. Once you have the value of W, substitute it back into Equation 1 to find the value of L.

Finally, you will have the length (L) and width (W) of the rectangle.