$\"\"$

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The system of equations is $\"\"$ .

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Subtract first and second equations

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$\"\"$

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Add 80 to each side.

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$\"\"$

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$\"\"$ $\"\"$

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Take out common factor 4.

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$\"\"$

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Factors the left side $\"\"$ .

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$\"\"$

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Apply zero product property: ab = 0, then a = 0, b = 0. \ \

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$\"\"$

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$\"\"$ $\"\"$

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Now solve for y, substitute x = 5 in $\"\"$ .

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$\"\"$

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$\"\"$

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Subtract 20 from each side.

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$\"\"$

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$\"\"$

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$\"\"$ \ \

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$\"\"$

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Find the value of x, and substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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Add 16 to each side.

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$\"\"$

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$\"\"$

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The power of $\"\"$ . \ \

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Apply square roots on each side and eliminate the squares.

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$\"\"$

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$\"\"$

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The solutions of them system are $\"\"$ .