WEBVTT

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Here is the problem: 3x plus 13 equals negative 9.

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A linear equation in x: isolate x using inverse operations.

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Start with the equation.

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Subtract 13 from both sides.

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Divide both sides by 3.

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So the answer is x equals negative 22 over 3 approximately negative 7.3333333.

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Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves x alone.

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x equals negative 7.3333333: left side equals negative 9, right side equals negative 9, which checks out.