2C - Linear inequations
2C - Content video: Linear inequations
This video covers the theory and several examples relating to how to solve linear inequations, including how to solve using a CAS calculator.
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Solving linear inequations:
We follow the same method to solve linear inequations as we did when solving linear equations.
We follow the same method to solve linear inequations as we did when solving linear equations.
■ When solving, if you multiply or divide by a negative number, you must reverse the sign of the inequality.
- Consider the correct inequality \(10>4\), if both sides are multiplied by \(-1\) we would have \(-10>-4\); however, this inequality statement is incorrect. By reversing the inequality sign we obtain a correct statement once again \(-10<-4\).
- Similarly, if we switch the expressions on each side of the inequality we also need to reverse the inequality sign. For example: \(4<x\) is equivalent to \(x>4\).
Using CAS to solve linear inequations:
Linear inequation can be solved using the solve command on the CAS calculator. To use the command:
Linear inequation can be solved using the solve command on the CAS calculator. To use the command:
Highlight the equation → Interactive → Equation/inequality → Solve
Make sure the variable you are solving for is listed on the screen (to change the variable use the Var keyboard).