Algebra 1 : How to add polynomials

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #22 : Polynomials

Simplify this expression:\(\displaystyle (2y)(4x^2z^2 + 2a^2b^2) + (5x^2z^2y + 7a^2b^2y)\)

Possible Answers:

\(\displaystyle 11y + a^2 b^2 y+13 x^2 y z^2\)

\(\displaystyle a^2 b^2 y+13 x^2 y z^2\)

\(\displaystyle 11 a^2 b^2 y+13 x^2 y z^2\)

\(\displaystyle 11 a^2 b^2 y + 15 x^2 y z^2\)

Not able to simplify further

Correct answer:

\(\displaystyle 11 a^2 b^2 y+13 x^2 y z^2\)

Explanation:

Don't be scared by complex terms! First, we follow our order of operations and multiply the \(\displaystyle y\) into the first binomial. Then, we check to see if the variables are alike. If they match perfectly, we can add and subtract their coefficients just like we could if the expression was \(\displaystyle 3x + 3x\).

Remember, a variable is always a variable, no matter how complex! In this problem, the terms match after we follow our order of operations! So we just add the coefficients of the matching terms and we get our answer:\(\displaystyle 11 a^2 b^2 y+13 x^2 y z^2\)

Example Question #11 : How To Add Polynomials

Simplify the following:  \(\displaystyle (x^3+2x-1)+(-2x^3-1)\)

Possible Answers:

\(\displaystyle x^3+2x\)

\(\displaystyle x^3+2x-2\)

\(\displaystyle -x^3-2x-2\)

\(\displaystyle -x^3+2x\)

\(\displaystyle -x^3+2x-2\)

Correct answer:

\(\displaystyle -x^3+2x-2\)

Explanation:

To solve \(\displaystyle (x^3+2x-1)+(-2x^3-1)\), identify all the like-terms and regroup to combine the values.

\(\displaystyle x^3-2x^3+2x-1-1= -x^3+2x-2\)

 

Example Question #12 : How To Add Polynomials

Evaluate the following expression:

\(\displaystyle (x^3 +3x^2 -2x-7)+(2x^3+3x+6)\)

Possible Answers:

\(\displaystyle 3x^3 +3x -1\)

\(\displaystyle 3x^3 +3x^2 +x -1\)

\(\displaystyle 2x^3 +3x^2 -x -1\)

\(\displaystyle 4x^3 +3x^2 -x +1\)

\(\displaystyle 3x^3 +6x^2 -2x -1\)

Correct answer:

\(\displaystyle 3x^3 +3x^2 +x -1\)

Explanation:

To add two polynomials together, you combine all like terms.

Combining the \(\displaystyle x^3\) terms gives us \(\displaystyle 3x^3\)

Combining the \(\displaystyle x^2\) terms gives us \(\displaystyle 3x^2\), since there is only 1 of those terms in the expression it remains the same.

Combining the \(\displaystyle x\) terms gives us \(\displaystyle x\)

and finally combining theconstants gives us \(\displaystyle -1\)

summing all these together gives us 

\(\displaystyle 3x^3 +3x^2 +x -1\)

Example Question #94 : Polynomial Operations

Simplify the following expression:

\(\displaystyle \left ( 3z + 18x\right ) + \left ( 15z + 4x\right )\)

Possible Answers:

\(\displaystyle 18z + 22x\)

\(\displaystyle 21zx + 19zx\)

\(\displaystyle 15z + 14x\)

\(\displaystyle 12z + 22x\)

\(\displaystyle 7z + 33x\)

Correct answer:

\(\displaystyle 18z + 22x\)

Explanation:

To add polynomials, simply group by like terms and perform the indicated operation. Remember, only like-variables can be added to one another:

\(\displaystyle \left ( 3z + 18x\right ) + \left ( 15z + 4x\right )\)

\(\displaystyle \left ( 3z + 15z\right ) + \left ( 18x + 4x\right )\)

\(\displaystyle 18z + 22x\)  is the simplest form of this expression.

Example Question #95 : Polynomial Operations

Simplify the following expression:

\(\displaystyle 7x^{2}+3xy-16x^{2}+4y-7xy\)

Possible Answers:

\(\displaystyle -9xy\)

\(\displaystyle 23x^{2}+10xy+4y\)

\(\displaystyle 23x^{2}+4y^{2}\)

\(\displaystyle -9x^{2}-4xy+4y\)

\(\displaystyle 7(x+3)(x-2)\)

Correct answer:

\(\displaystyle -9x^{2}-4xy+4y\)

Explanation:

\(\displaystyle 7x^{2}+3xy-16x^{2}+4y-7xy\)

Collect like terms.

\(\displaystyle 7x^{2}-16x^{2}+3xy-7xy+4y\)

\(\displaystyle -9x^{2}-4xy+4y\)

Example Question #161 : Variables

Simplify the following expression:

\(\displaystyle 3x^{2}y^{2}+4x^{2}+6y+4x^{2}y^{2}+2y+12\)

Possible Answers:

\(\displaystyle 7x^2y^2 + 12x^2y +12\)

\(\displaystyle 31x^6y^6\)

\(\displaystyle 7x^4y^4 + 4x^2 +8y^2 +12\)

\(\displaystyle 11x^2+2y^2+8y+12\)

\(\displaystyle 7x^2y^2 + 4x^2 +8y +12\)

Correct answer:

\(\displaystyle 7x^2y^2 + 4x^2 +8y +12\)

Explanation:

In order to simplify this expression, we need to add together like terms. What this means, is that we can only add together different parts of the expression that have the same kind of variable. For example, \(\displaystyle 3x^{2}y^{2}\) can only be added to other values that also have \(\displaystyle x^{2}y^{2}\). We cannot combine \(\displaystyle 3x^{2}y^{2}\) to values that do not have the same exact variable - so, we cannot combine it with \(\displaystyle 4x^{2}\), or \(\displaystyle 6y\), and so on. Everything about the variables of two terms needs to be exactly the same if we are going to be able to combine them - the only thing that can be different are the coefficients (the numbers in front of the variables).

 

So, let's look at the expression above, and see if there are any like terms that we can combine.

Starting with \(\displaystyle 3x^{2}y^{2}\) - in order to be combined with this term, any other term must have \(\displaystyle x^{2}y^{2}\) as their variable. There is one other term in this expression tha thas \(\displaystyle x^{2}y^{2}\) as their variable - \(\displaystyle 4x^{2}y^{2}\). If two terms hae the exact same variables, the only thing that we need to do in order to combine them is to add their coefficients together:

\(\displaystyle 3x^{2}y^{2}+4x^{2}y^{2}= 7x^{2}y^{2}\)

 

Now, let's look at the next term in the expression, \(\displaystyle 4x^2\). There are no other terms that have \(\displaystyle x^2\) as their variable, so this term will stay the same.

 

Now, let's look at \(\displaystyle 6y\). There is one other term that has \(\displaystyle y\) as their vairable: \(\displaystyle 2y\). Let's add these two terms together:

\(\displaystyle 6y +2y = 8y\)

 

Finally, let's look at our last term which happens to have no variable: \(\displaystyle 12\). There are no other terms in the expression that have no variable, so this term will stay the same.

Now, let's add together all of our simplified terms, as well as the terms that could not be simplified:

\(\displaystyle 7x^2y^2 + 4x^2 +8y +12\)

This is our simplified answer.

 

 

Example Question #96 : Polynomial Operations

Simplify the following:

\(\displaystyle 3(x^2 + 4x) + 12x + 5\)

Possible Answers:

\(\displaystyle 3x^2 - 12x + 5\)

\(\displaystyle 3x^2 + 12 x + 5\)

\(\displaystyle 3x^2 + 12\)

\(\displaystyle 3x^2 + 5\)

\(\displaystyle 3x^2 + 24x + 5\)

Correct answer:

\(\displaystyle 3x^2 + 24x + 5\)

Explanation:

To solve this problem, first distribute anything through parentheses that needs to be distributed, then combine all terms with like variables (i.e. same variable, same exponent):

\(\displaystyle 3x^2 + 12 x + 12x + 5\)

\(\displaystyle 3x^2 + 24x + 5\)

Example Question #13 : How To Add Polynomials

Simplify the following:

\(\displaystyle (10x^2 + 5) + (x(3 + x))\)

Possible Answers:

\(\displaystyle 10x^2 + 3x + 5 + x\)

\(\displaystyle 10x^2 + 3x + 5\)

\(\displaystyle x + 10 + 5 + 3\)

\(\displaystyle 11x^2 + 3x + 5\)

\(\displaystyle x^2 + 18\)

Correct answer:

\(\displaystyle 11x^2 + 3x + 5\)

Explanation:

To solve this problem, first distribute anything through parentheses that needs to be distributed, then combine all terms with like variables (i.e. same variable, same exponent):

\(\displaystyle (10x^2 + 5) + (x(3 + x))\)

 

\(\displaystyle 10x^2 + 5 + 3x + x^2\)

\(\displaystyle 11x^2 + 3x + 5\)

Example Question #101 : Polynomial Operations

Simplify the following:

\(\displaystyle (2(x + 5)) + (3x^2 + x + 1)\)

Possible Answers:

\(\displaystyle x^2 + x + 11/2\)

\(\displaystyle x^2 + 6x + 11\)

\(\displaystyle 3x^2 + 3x + 11\)

\(\displaystyle 6x ^2 + 11x + 3\)

\(\displaystyle 11 + x^2 + 6x\)

Correct answer:

\(\displaystyle 3x^2 + 3x + 11\)

Explanation:

To solve this problem, first distribute anything through parentheses that needs to be distributed, then combine all like terms (i.e. same variable, same exponent):

\(\displaystyle (2(x + 5)) + (3x^2 + x + 1)\)

\(\displaystyle 2x +10 +3x^2 + x + 1\)

\(\displaystyle 3x^2 + 3x + 11\)

 

Example Question #11 : How To Add Polynomials

Simplify the following:

\(\displaystyle (y(3 + x)) + (x(y + 1))\)

Possible Answers:

\(\displaystyle 2y + 3xy + x\)

\(\displaystyle y + 3xy + x\)

\(\displaystyle 3y +2xy + x\)

\(\displaystyle y + xy + x\)

\(\displaystyle 3y + xy + xy + x\)

Correct answer:

\(\displaystyle 3y +2xy + x\)

Explanation:

To solve this problem, first distribute anything through parentheses that needs to be distributed, then combine all terms with like variables (i.e. same variable, same exponent):

\(\displaystyle (y(3 + x)) + (x(y + 1))\)

 

\(\displaystyle 3y + xy + xy + x\)

\(\displaystyle 3y + 2xy + x\)

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