WEBVTT

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Here is the problem: (x plus y plus 1) squared.

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Expand (x plus y plus 1) squared and collect like terms.

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Read the expression.

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Expand powers of sums. Write (a plus b) to the power n as repeated multiplication and multiply out; e.g. (a plus b) squared equals a squared plus 2ab plus b squared.

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Result after multiplying out.

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Write the result in standard form. Terms are ordered by descending total degree.

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So the answer is x squared plus 2xy plus y squared plus 2x plus 2y plus 1.

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After expanding and combining like terms the expression is x squared plus 2xy plus y squared plus 2x plus 2y plus 1, a polynomial of degree 2 with 6 terms.

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Spot check at x equals 0.73, y equals 1.14: original 8.2369, simplified 8.2369, which checks out.