Determining Whether an Integer is a Solution to an Equation
Learning Outcomes
- Determine whether an integer is a solution to an equation
Determine Whether an Integer is a Solution of an Equation
In Solve Equations with the Subtraction and Addition Properties of Equality, we saw that a solution of an equation is a value of a variable that makes a true statement when substituted into that equation. In that section, we found solutions that were whole numbers. Now that we’ve worked with integers, we’ll find integer solutions to equations. The steps we take to determine whether a number is a solution to an equation are the same whether the solution is a whole number or an integer.How to determine whether a number is a solution to an equation
- Substitute the number for the variable in the equation.
- Simplify the expressions on both sides of the equation.
- Determine whether the resulting equation is true.
- If it is true, the number is a solution.
- If it is not true, the number is not a solution.
example
Determine whether each of the following is a solution of [latex]2x - 5=-13\text{:}[/latex] 1. [latex]x=4[/latex] 2. [latex]x=-4[/latex] 3. [latex]x=-9[/latex]. Solution1. Substitute [latex]4[/latex] for x in the equation to determine if it is true. | |
Substitute [latex]\color{red}{4}[/latex] for x. | [latex]2x--5=--13[/latex] |
[latex]2(\color{red}{4})--5=--13[/latex] | |
Multiply. | [latex]8--5=--13[/latex] |
Subtract. | [latex]3=--13[/latex] |
2. Substitute [latex]−4[/latex] for x in the equation to determine if it is true. | |
Substitute [latex]\color{red}{--4}[/latex] for x. | [latex]2x--5=--13[/latex] |
Multiply. | [latex]--8--5=--13[/latex] |
Subtract. | [latex]--13=--13[/latex] |
3. Substitute [latex]−9[/latex] for x in the equation to determine if it is true. | |
[latex]2x--5=--13[/latex] | |
Substitute [latex]−9[/latex] for x. | [latex]2(\color{red}{--9})--5=--13[/latex] |
Multiply. | [latex]--18--5=--13[/latex] |
Subtract. | [latex]--23=--13[/latex] |
try it
[ohm_question]146556[/ohm_question]Licenses & Attributions
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- Question ID 146556. Provided by: ` Authored by: Lumen Learning. License: CC BY: Attribution. License terms: MathAS Community License.
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- Introduction to Algebraic Equations (L5.1). Authored by: James Sousa (Mathispower4u.com). License: CC BY: Attribution.
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- Prealgebra. Provided by: OpenStax License: CC BY: Attribution. License terms: Download for free at http://cnx.org/contents/[email protected].