$\"\"$

The equations are

$\"\"$ Equation (1)

$\"\"$ Equation (2)

$\"\"$

Subtract equation (2) from (1).

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Divide each side by 2.

$\"\"$

Substitute $\"\"$ in equation (1).

$\"\"$

Apply subtraction property of equality: if a = b, then $\"\"$ .

Subtract 4 from each side.

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The solution is $\"\"$ .