To find the length of the pool, we first need to find an expression for the width in terms of x.
Given that the width w is x + 4, the length L can be expressed as:
L = x + 4
Now, we can use the formula for the area of a rectangle (A = L * w) to find an expression for the length:
A = x^3 - 13x + 12
A = (x + 4)(x - 3)
Since A = L * w, we can set it equal to the given area expression and solve for L:
(x + 4)(x - 3) = x^3 - 13x + 12
x^2 + x - 12 = x^3 - 13x + 12
x^3 - x^2 - 14x + 24 = 0
Now, let's factor the equation by grouping:
x^2(x - 1) - 12(x - 1) = 0
(x^2 - 12)(x - 1) = 0
(x + √12)(x - √12)(x - 1) = 0
Therefore, the length of the pool can be expressed as:
L = x + √12
The width w of a rectangular swimming pool is x plus 4. The area A of the pool is x cubed minus 13 x plus 12. What is an expression for the length of the pool?
5 answers
solve using long division
To find the length of the pool, we first need to find an expression for the width in terms of x.
Given that the width w is x + 4, the length L can be expressed as:
L = x + 4
Now, we can use the formula for the area of a rectangle (A = L * w) to find an expression for the length:
A = x^3 - 13x + 12
Since A = L * w, we can set it equal to the given area expression and solve for L:
L*(x + 4) = x^3 - 13x + 12
Expanding the left side:
Lx + 4L = x^3 - 13x + 12
Substituting L = x + 4:
(x + 4)x + 4(x + 4) = x^3 - 13x + 12
x^2 + 4x + 4(x + 4) = x^3 - 13x + 12
x^2 + 4x + 4x + 16 = x^3 - 13x + 12
x^2 + 8x + 16 = x^3 - 13x + 12
Rearranging terms:
x^3 - x^2 - 21x + 4 = 0
Now, we can use long division to find the quotient, which will give us the length of the pool. The quotient of x^3 - x^2 - 21x + 4 divided by (x + 4) is:
x^2 - 5x + 1
Therefore, the length of the pool can be expressed as:
L = x^2 - 5x + 1
Given that the width w is x + 4, the length L can be expressed as:
L = x + 4
Now, we can use the formula for the area of a rectangle (A = L * w) to find an expression for the length:
A = x^3 - 13x + 12
Since A = L * w, we can set it equal to the given area expression and solve for L:
L*(x + 4) = x^3 - 13x + 12
Expanding the left side:
Lx + 4L = x^3 - 13x + 12
Substituting L = x + 4:
(x + 4)x + 4(x + 4) = x^3 - 13x + 12
x^2 + 4x + 4(x + 4) = x^3 - 13x + 12
x^2 + 4x + 4x + 16 = x^3 - 13x + 12
x^2 + 8x + 16 = x^3 - 13x + 12
Rearranging terms:
x^3 - x^2 - 21x + 4 = 0
Now, we can use long division to find the quotient, which will give us the length of the pool. The quotient of x^3 - x^2 - 21x + 4 divided by (x + 4) is:
x^2 - 5x + 1
Therefore, the length of the pool can be expressed as:
L = x^2 - 5x + 1
try again
To find the length of the pool, we can use the formula for the area of a rectangle, which is:
A = L * W
Given that the width W of the pool is x + 4, and the area A is x^3 - 13x + 12, we can set up the following equation:
x^3 - 13x + 12 = L * (x + 4)
Expanding the right side of the equation:
x^3 - 13x + 12 = Lx + 4L
Since we know the width W is x + 4, we can express L in terms of x by dividing both sides by x + 4:
(x^3 - 13x + 12)/(x + 4) = L
Now, we will use long division to divide x^3 - 13x + 12 by x + 4 to find the expression for the length L:
x^2 - 4x + 1
_______________
x + 4 | x^3 - 13x + 12
- x^3 + 4x^2
_____________
- 17x + 12
+ 17x + 68
_____________
80
Therefore, the expression for the length of the pool is:
L = x^2 - 4x + 1
A = L * W
Given that the width W of the pool is x + 4, and the area A is x^3 - 13x + 12, we can set up the following equation:
x^3 - 13x + 12 = L * (x + 4)
Expanding the right side of the equation:
x^3 - 13x + 12 = Lx + 4L
Since we know the width W is x + 4, we can express L in terms of x by dividing both sides by x + 4:
(x^3 - 13x + 12)/(x + 4) = L
Now, we will use long division to divide x^3 - 13x + 12 by x + 4 to find the expression for the length L:
x^2 - 4x + 1
_______________
x + 4 | x^3 - 13x + 12
- x^3 + 4x^2
_____________
- 17x + 12
+ 17x + 68
_____________
80
Therefore, the expression for the length of the pool is:
L = x^2 - 4x + 1