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Praxis Core Math
Unit 1: Lesson 4
Algebra- Algebraic properties | Lesson
- Algebraic properties | Worked example
- Solution procedures | Lesson
- Solution procedures | Worked example
- Equivalent expressions | Lesson
- Equivalent expressions | Worked example
- Creating expressions and equations | Lesson
- Creating expressions and equations | Worked example
- Algebraic word problems | Lesson
- Algebraic word problems | Worked example
- Linear equations | Lesson
- Linear equations | Worked example
- Quadratic equations | Lesson
- Quadratic equations | Worked example
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Linear equations | Lesson
What are linear equations?
A linear equation is an equation with and one or more constants. For example, in the linear equation start color #11accd, 2, end color #11accd, x, plus, start color #ca337c, 3, end color #ca337c, equals, start color #ca337c, 4, end color #ca337c:
- x is the variable, which represents a number whose value we don't know yet.
- start color #11accd, 2, end color #11accd is the coefficient, or the constant multiple of the variable x. Together, start color #11accd, 2, end color #11accd, x is a single .
- start color #ca337c, 3, end color #ca337c and start color #ca337c, 4, end color #ca337c are constants. They are both terms as well.
Solving a linear equation means finding the value(s) for the variable(s) that make the equation true.
What skills are tested?
- Solving linear equations with one variable
How do we solve linear equations?
Our goal when solving linear equations with one variable is to find the value of the variable that makes the equation true. To do this, we need to by identifying to perform on both sides of the equation until the variable is left by itself.
- Addition and subtraction are inverse operations.
- Multiplication and division are inverse operations.
For , it's easiest if we first combine the constant terms on one side of the equation and the x-terms on the other side of the equation. Then, isolate x.
What features make linear equations more difficult?
Below are features that make solving linear equations more challenging and tips for handling them.
Negative numbers
When working with negative numbers, remember that:
- start text, n, e, g, a, t, i, v, e, end text, times, start text, n, e, g, a, t, i, v, e, end text, equals, start text, p, o, s, i, t, i, v, e, end text
- start text, p, o, s, i, t, i, v, e, end text, times, start text, n, e, g, a, t, i, v, e, end text, equals, start text, n, e, g, a, t, i, v, e, end text
Fractions
When solving a linear equation with fraction coefficients or constants:
- If the equation has only a fraction coefficient, consider leaving the fraction until the last step in isolating x.
- If the equation has both fraction coefficients and fraction constants, consider getting rid of the fractions in the first step.
More than one variable term
When solving a linear equation with multiple terms containing the variable, we need to combine . Just as constants can be added and subtracted, like terms can be combined by adding and subtracting the coefficients and keeping the variable the same:
a, x, plus minus, b, x, equals, left parenthesis, a, plus minus, b, right parenthesis, x
Coefficients to distribute
When distributing coefficients, observe the distributive property:
a, left parenthesis, b, x, plus minus, c, right parenthesis, equals, a, b, x, plus minus, a, c
Your turn!
Things to remember
To solve a linear equation, we find the value of the variable that makes the equation true by:
- Distributing any coefficients.
- Combining any like terms.
- Isolating the variable.
Want to join the conversation?
I Just failed my quiz for school and this really is not helping on performing operations on linear equations and I can't ask my siblings, and I can't find any thing on here to help me! Somebody help me!(3 votes)- Wow i had a test on this today and i gto a really good score(2 votes)
- I'm more confused after watching this one.(2 votes)
- And what app do you use i really need it(1 vote)
- what should I do next? I am scheduled to take the praxis 8/19/22.(1 vote)
- In the tips section, you clearly state to you the inverse operation to isolate variables. Yet, in your last example, you use the same operation, instead of the inverse. How does this help? It confuses.(1 vote)
In the last example it is a fraction, a fraction symbolizes dividing I guess so the inverse would be multiplying, or you could also just multiply 4 by the reciprocal so yeah.(1 vote)