Simplifying Algebraic Expressions
Site: | Saylor Academy |
Course: | GKT101: General Knowledge for Teachers – Math |
Book: | Simplifying Algebraic Expressions |
Printed by: | Guest user |
Date: | Wednesday, May 14, 2025, 8:10 AM |
Description
You can use two main tools to simplify or rewrite algebraic expressions: combining like terms and using the distributive property. Watch this lecture series and complete the interactive exercises to practice these skills.
Table of contents
- Intro to combining like terms
- Combining like terms with negative coefficients & distribution
- Combining like terms with negative coefficients
- Combining like terms with rational coefficients
- Combining like terms with negative coefficients - Questions
- Combining like terms with negative coefficients & distribution - Questions
- Combining like terms with rational coefficients - Questions
Intro to combining like terms
Source: Khan Academy, https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra#x2f8bb11595b61c86:combine-like-terms This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.
Combining like terms with negative coefficients & distribution
Combining like terms with negative coefficients
Combining like terms with rational coefficients
Combining like terms with negative coefficients - Questions
1. Combine the like terms to create an equivalent expression: \(−n+(−4)−(−4n)+6\)
2. Combine the like terms to create an equivalent expression: \( -2 x-x+8\)
3. Combine the like terms to create an equivalent expression: \(2 s+(-4 s)\)
4. Combine the like terms to create an equivalent expression: \(-3 x-6+(-1)\)
5. Combine the like terms to create an equivalent expression: \(2 r+1+(-4 r)+7\)
6 . Combine the like terms to create an equivalent expression: \(−5r+8r+5\)
7. Combine the like terms to create an equivalent expression: \(r+(−5r)\)
Answers
1. Combine the \(n\) terms:
\(\begin{aligned}
-n+(-4)-(-4 n)+6 &=(-1+4) n-4+6 \\
&=3 n-4+6
\end{aligned}\)
Combine the numeric terms:
\(3 n-4+6=3 n+2\)
The simplified expression is \(3n + 2\).
2. Combine the \(x\) terms:
\(\begin{aligned}
-2 x-x+8 &=(-2-1) x+8 \\
&=-3 x+8
\end{aligned}\)
The simplified expression is \( -3x + 8 \).
3. Combine the \(s\) terms:
\(\begin{aligned}
2 s+(-4 s) &=(2-4) s \\
&=-2 s
\end{aligned}\)
The simplified expression is \(-2s\).
4. Combine the numeric terms:
\(-3 x-6-1=-3 x-7\)
The simplified expression is \(-3x - 7\).
5. Combine the \(r\) terms:
\(\begin{aligned}
2 r+1+(-4 r)+7 &=(2-4) r+1+7 \\
&=-2 r+1+7
\end{aligned}\)
Combine the numeric terms:
\(−2r+1+7=−2r+8\)
The simplified expression is \(-2r +8\).
6. Combine the \(r\) terms:
\( \begin{aligned}
-5 r+8 r+5 &=(-5+8) r+5 \\
&=3 r+5
\end{aligned}\)
The simplified expression is \(3r + 5\).
7. Combine the \(r\) terms:
\(\begin{aligned}
r+(-5 r) &=(1-5) r \\
&=-4 r
\end{aligned}\)
The simplified expression is \(-4r\).
Combining like terms with negative coefficients & distribution - Questions
1. Simplify to create an equivalent expression. \(2(−2−4p)+2(−2p−1)\)
Choose 1 answer:
A. \(−12p−6\)
B. \(-10p - 6\)
C. \(-12p+6\)
D. \(12p-6\)
2. Simplify to create an equivalent expression. \(1+4(6p−9)\)
Choose 1 answer:
A. \(6p−35\)
B. \(24p−35\)
C. \(24p−36\)
D. \(6p−36\)
3. Simplify to create an equivalent expression. \(4(−15−3p)−4(−p+5) \)
A. \(−8p−80 \)
B. \(−13p−80 \)
C. \(−8p+80\)
D. \(8p-80\)
4. Simplify to create an equivalent expression. \(2−4(5p+1) \)
A. \(−20p−2\)
B. \(−5p−4\)
C. \(−20p+2\)
D. \(−5p+4\)
Answers
1. A. \(−12p−6\)
2. B. \(24p−35\)
3. A. \(−8p−80 \)
4. A. \(−20p−2\)
Combining like terms with rational coefficients - Questions
1. Combine like terms to create an equivalent expression. \( −2.5(4x−3)\)
2. Combine like terms to create an equivalent expression. \(1.3b+7.8−3.2b\)
3. Combine like terms to create an equivalent expression. \(-\frac{2}{3} p+\frac{1}{5}-1+\frac{5}{6} p\)
Enter any coefficients as simplified proper or improper fractions or integers.
4. Combine like terms to create an equivalent expression. \(\frac{1}{7}-3\left(\frac{3}{7} n-\frac{2}{7}\right)\)
Enter any coefficients as simplified proper or improper fractions or integers.
Answers
1. Use the distributive property to multiply the \(-2.5\) into the parentheses.
= \(−2.5(4x−3)\)
= \(−2.5⋅(4x)+(−2.5)⋅(−3)\)
We expanded the expression by multiplying the \(-2.5\) by both terms in the parentheses.
=\(-10x+7.5\)
The expanded expression is \(-10x+7.5\).
2. Combine the coefficients of the \(b\) terms.
= \(=1.3b+7.8−3.2b\)
= \((1.3−3.2)⋅b+7.8\)
= \((−1.9)⋅b+7.8\)
= \(−1.9b+7.8\)
The simplified expression is \(−1.9b+7.8 \).
3. Combine the coefficients of the \(p\) terms, and combine the constant terms.
= \(-\frac{2}{3} p+\frac{1}{5}-1+\frac{5}{6} p\)
= \(\left(-\frac{2}{3}+\frac{5}{6}\right) \cdot p+\frac{1}{5}-1 \)
Group the \(p\) coefficients together, and group the numeric coefficients together.
= \(\left(-\frac{4}{6}+\frac{5}{6}\right) \cdot p+\frac{1}{5}-\frac{5}{5} \)
Rewrite \(−1\) as \(-\frac{5}{5}\) to form common denominators.
= \(\left(\frac{1}{6}\right) \cdot p-\frac{4}{5}\)
=\(\frac{1}{6} p-\frac{4}{5}\)
The simplified expression is \(\frac{1}{6} p-\frac{4}{5}\).
4. Use the distributive property to multiply the \(-3\) into the parentheses.
= \(\frac{1}{7}-3\left(\frac{3}{7} n-\frac{2}{7}\right)\)
= \( \frac{1}{7}+(-3) \cdot\left(\frac{3}{7} n\right)+(-3) \cdot\left(-\frac{2}{7}\right)\)
We expanded the expression by multiplying the \(-3\) by both terms in the parentheses.
= \(\frac{1}{7}-\frac{9}{7} n+\frac{6}{7} \)
= \(-\frac{9}{7} n+\frac{7}{7}\)
We combined the numeric terms.
= \(-\frac{9}{7} n+1\)
The expanded expression is \(-\frac{9}{7} n+1\).