$\"\"$

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Substitution:

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Given equations are,

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$\"\"$ ----------(1)

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$\"\"$ ------(2)

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The first equation is already solved for y,

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so, substitute $\"\"$ for y in the second equation.

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$\"\"$ (Second equation)

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$ (Multiply: $\"\"$ )

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$\"\"$ (Add: $\"\"$ )

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Apply division property of equality: If a = b then $\"\"$ .

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$\"\"$ (Divide each side by 20)

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$\"\"$ (Cancel common terms)

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$\"\"$ (Divide: $\"\"$ ) $\"\"$

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Substitute $\"\"$ for x in either equation to find y.

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$\"\"$ (first equation)

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$\"\"$ (Substitute $\"\"$ )

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$\"\"$ (Multiply: $\"\"$ )

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The solution is $\"\"$ . $\"\"$

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Check the solution:

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To check, Substitute $\"\"$ and $\"\"$ in either equation.

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$\"\"$ (first equation)

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$\"\"$ (Substitute $\"\"$ and $\"\"$ )

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$\"\"$ (Multiply: $\"\"$ )

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The solution is true.

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If the system have only one solution, such as $\"\"$ . $\"\"$

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If the system have only one solution, such as $\"\"$ .