Chapter 4: Problem 53
53\. Simplify: \(\frac{5 x^{4}(2 x+7)^{4}-8 x^{5}(2 x+7)^{3}}{(2 x+7)^{8}}\)
Short Answer
Expert verified
\[ \frac{x^4 (2x + 35)}{(2x + 7)^5} \]
Step by step solution
01
Factor out common terms in the numerator
Both terms in the numerator share common factors. Identify the greatest common factor: \[ 5x^4 (2x+7)^4 \text{ and } 8x^5 (2x+7)^3 \]Factor out \( x^4 (2x+7)^3 \): \[ 5x^4 (2x+7)^4 - 8x^5 (2x+7)^3 = (2x+7)^3 x^4 [5(2x+7) - 8x] \]
02
Simplify inside the brackets
Simplify the expression inside the brackets: \[ 5(2x + 7) - 8x = 10x + 35 - 8x = 2x + 35 \]So the expression now becomes: \[ x^4 (2x+7)^3 (2x + 35) \]
03
Substitute back into the fraction
Place the simplified numerator back into the original fraction: \[ \frac{x^4 (2x + 7)^3 (2x + 35)}{(2x + 7)^8} \]
04
Simplify the fraction
Cancel common factors between the numerator and the denominator: \[ \frac{x^4 (2x + 7)^3 (2x + 35)}{(2x + 7)^8} = \frac{x^4 (2x + 35)}{(2x + 7)^5} \]
05
Final simplified form
The simplified form of the given expression is: \[ \frac{x^4 (2x + 35)}{(2x + 7)^5} \]
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with Vaia!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Factoring Polynomials
When dealing with complex polynomial expressions, one of the key steps is to factor them. Factoring simply means breaking down the polynomial into simpler, multipliable terms. This process makes it easier to simplify, solve, or understand the expression.
In our exercise, the expression in the numerator, \[ 5x^4 (2x+7)^4 - 8x^5 (2x+7)^3 \], can be factored by identifying the greatest common factor (GCF). The GCF here is \[ x^4 (2x+7)^3 \]. Factoring this out leaves us with \[ (2x+7)^3 x^4 [5(2x+7) - 8x] \].
To verify your factoring, multiply the factors back together to ensure you get the original polynomial. This step is crucial for checking your work and ensuring the expression was factored correctly.
In our exercise, the expression in the numerator, \[ 5x^4 (2x+7)^4 - 8x^5 (2x+7)^3 \], can be factored by identifying the greatest common factor (GCF). The GCF here is \[ x^4 (2x+7)^3 \]. Factoring this out leaves us with \[ (2x+7)^3 x^4 [5(2x+7) - 8x] \].
To verify your factoring, multiply the factors back together to ensure you get the original polynomial. This step is crucial for checking your work and ensuring the expression was factored correctly.
Simplifying Expressions
Simplifying algebraic expressions involves combining like terms and reducing the expression to its lowest terms.
It is essential to follow the order of operations (PEMDAS/BODMAS: Parentheses/Brackets, Exponents/Orders, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).
In our exercise, after factoring out the GCF, we simplify the expression inside the brackets: \[ 5(2x + 7) - 8x = 10x + 35 - 8x = 2x + 35 \].
Simplifying within parentheses first ensures that the rest of the expression is handled correctly. This step was important to reduce the expression to \[ x^4 (2x + 7)^3 (2x + 35) \], making it easier to work with moving forward.
It is essential to follow the order of operations (PEMDAS/BODMAS: Parentheses/Brackets, Exponents/Orders, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).
In our exercise, after factoring out the GCF, we simplify the expression inside the brackets: \[ 5(2x + 7) - 8x = 10x + 35 - 8x = 2x + 35 \].
Simplifying within parentheses first ensures that the rest of the expression is handled correctly. This step was important to reduce the expression to \[ x^4 (2x + 7)^3 (2x + 35) \], making it easier to work with moving forward.
Algebraic Fractions
An algebraic fraction is a fraction where the numerator and/or the denominator are algebraic expressions (expressions that include variables). Simplifying these fractions typically involves factoring and reducing common terms.
In our example, the fraction to simplify is \[ \frac{5 x^{4}(2 x+7)^{4}-8 x^{5}(2 x+7)^{3}}{(2 x+7)^{8}} \].
By factoring and simplifying the numerator first, we substitute it back into the fraction: \[ \frac{x^4 (2x + 7)^3 (2x + 35)}{(2x + 7)^8} \].
Next, we identify and cancel out the common factors in both the numerator and the denominator. Here, \[ (2x + 7)^3 \] is present in both, so we cancel it out, resulting in \[ \frac{x^4 (2x + 35)}{(2x + 7)^5} \].
Simplifying algebraic fractions helps in making complex expressions more manageable and easier to understand. This final step of cancellation is essential for finding the simplest form of the fraction.
In our example, the fraction to simplify is \[ \frac{5 x^{4}(2 x+7)^{4}-8 x^{5}(2 x+7)^{3}}{(2 x+7)^{8}} \].
By factoring and simplifying the numerator first, we substitute it back into the fraction: \[ \frac{x^4 (2x + 7)^3 (2x + 35)}{(2x + 7)^8} \].
Next, we identify and cancel out the common factors in both the numerator and the denominator. Here, \[ (2x + 7)^3 \] is present in both, so we cancel it out, resulting in \[ \frac{x^4 (2x + 35)}{(2x + 7)^5} \].
Simplifying algebraic fractions helps in making complex expressions more manageable and easier to understand. This final step of cancellation is essential for finding the simplest form of the fraction.