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Simplify the expression, show all of your work 18 : 2x3 / 5-2

2 Answers

3 votes

Answer:

2⋅(x 3 −5)

________

5

Explanation:

User Mehul Bisht
by
7.9k points
1 vote

Answer:

2⋅(x 3 −5)

________

5

Step-by-step explanation: I hope this really help!

Reformatting the input :

Changes made to your input should not affect the solution:

(1): "x3" was replaced by "x^3".

STEP

1

:

x3

Simplify ——

5

Equation at the end of step

1

:

x3

(2 • ——) - 2

5

STEP

2

:

Rewriting the whole as an Equivalent Fraction

2.1 Subtracting a whole from a fraction

Rewrite the whole as a fraction using 5 as the denominator :

2 2 • 5

2 = — = —————

1 5

Equivalent fraction : The fraction thus generated looks different but has the same value as the whole

Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator

Adding fractions that have a common denominator :

2.2 Adding up the two equivalent fractions

Add the two equivalent fractions which now have a common denominator

Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

2x3 - (2 • 5) 2x3 - 10

————————————— = ————————

5 5

STEP

3

:

Pulling out like terms

3.1 Pull out like factors :

2x3 - 10 = 2 • (x3 - 5)

Trying to factor as a Difference of Cubes:

3.2 Factoring: x3 - 5

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 : 5 is not a cube !!

Ruling : Binomial can not be factored as the difference of two perfect cubes

Polynomial Roots Calculator :

3.3 Find roots (zeroes) of : F(x) = x3 - 5

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 1 and the Trailing Constant is -5.

The factor(s) are:

of the Leading Coefficient : 1

of the Trailing Constant : 1 ,5

Let us test ....

P Q P/Q F(P/Q) Divisor

-1 1 -1.00 -6.00

-5 1 -5.00 -130.00

1 1 1.00 -4.00

5 1 5.00 120.00

Polynomial Roots Calculator found no rational roots

Final result :

2 • (x3 - 5)

————————————

5

User UnahD
by
7.7k points

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