WEBVTT

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Here is the problem: 8(x plus 5) equals 4x minus 7.

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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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Simplify each side (distribute and combine like terms).

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Subtract 4x from both sides.

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Subtract 40 from both sides.

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Divide both sides by 4.

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So the answer is x equals negative 47 over 4 approximately negative 11.75.

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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 11.75: left side equals negative 54, right side equals negative 54, which checks out.