Solution - Linear equations with one unknown
Other Ways to Solve
Linear equations with one unknownStep by Step Solution
Reformatting the input :
Changes made to your input should not affect the solution:
(1): "x4" was replaced by "x^4". 1 more similar replacement(s).
Rearrange:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
9*(x^1)-(2*x^4)=0
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(9 • (x1)) - 2x4 = 0Step 2 :
Equation at the end of step 2 :
32x - 2x4 = 0
Step 3 :
Step 4 :
Pulling out like terms :
4.1 Pull out like factors :
9x - 2x4 = -x • (2x3 - 9)
Trying to factor as a Difference of Cubes:
4.2 Factoring: 2x3 - 9
Theory : A difference of two perfect cubes, a3 - b3 can be factored into
(a-b) • (a2 +ab +b2)
Proof : (a-b)•(a2+ab+b2) =
a3+a2b+ab2-ba2-b2a-b3 =
a3+(a2b-ba2)+(ab2-b2a)-b3 =
a3+0+0-b3 =
a3-b3
Check : 2 is not a cube !!
Ruling : Binomial can not be factored as the difference of two perfect cubes
Polynomial Roots Calculator :
4.3 Find roots (zeroes) of : F(x) = 2x3 - 9
Polynomial Roots Calculator is a set of methods aimed at finding values of x for which F(x)=0
Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers x which can be expressed as the quotient of two integers
The Rational Root Theorem states that if a polynomial zeroes for a rational number P/Q then P is a factor of the Trailing Constant and Q is a factor of the Leading Coefficient
In this case, the Leading Coefficient is 2 and the Trailing Constant is -9.
The factor(s) are:
of the Leading Coefficient : 1,2
of the Trailing Constant : 1 ,3 ,9
Let us test ....
P | Q | P/Q | F(P/Q) | Divisor | |||||
---|---|---|---|---|---|---|---|---|---|
-1 | 1 | -1.00 | -11.00 | ||||||
-1 | 2 | -0.50 | -9.25 | ||||||
-3 | 1 | -3.00 | -63.00 | ||||||
-3 | 2 | -1.50 | -15.75 | ||||||
-9 | 1 | -9.00 | -1467.00 | ||||||
-9 | 2 | -4.50 | -191.25 | ||||||
1 | 1 | 1.00 | -7.00 | ||||||
1 | 2 | 0.50 | -8.75 | ||||||
3 | 1 | 3.00 | 45.00 | ||||||
3 | 2 | 1.50 | -2.25 | ||||||
9 | 1 | 9.00 | 1449.00 | ||||||
9 | 2 | 4.50 | 173.25 |
Polynomial Roots Calculator found no rational roots
Equation at the end of step 4 :
-x • (2x3 - 9) = 0
Step 5 :
Theory - Roots of a product :
5.1 A product of several terms equals zero.
When a product of two or more terms equals zero, then at least one of the terms must be zero.
We shall now solve each term = 0 separately
In other words, we are going to solve as many equations as there are terms in the product
Any solution of term = 0 solves product = 0 as well.
Solving a Single Variable Equation :
5.2 Solve : -x = 0
Multiply both sides of the equation by (-1) : x = 0
Solving a Single Variable Equation :
5.3 Solve : 2x3-9 = 0
Add 9 to both sides of the equation :
2x3 = 9
Divide both sides of the equation by 2:
x3 = 9/2 = 4.500
When two things are equal, their cube roots are equal. Taking the cube root of the two sides of the equation we get:
x = ∛ 9/2
The equation has one real solution
This solution is x = ∛ 4.500 = 1.65096
Two solutions were found :
- x = ∛ 4.500 = 1.65096
- x = 0
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