$\"\"$

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Megana, Emma and mora all went over their allotted phone plans.

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Gaming prices, call price and text prices are represented by equations.

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Let $\"\"$ be the cost of the gaming plan.

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Let $\"\"$ be the cost of the call plan.

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Let $\"\"$ be the cost of the message plan.

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The system of equations are

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Megana paid those three prices are $\"\"$ .

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Emma paid those three prices are $\"\"$ .

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Mora paid those three prices are $\"\"$ .

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Coefficient matrix $\"\"$ .

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Caluculate the determinant of matrix $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Cramer $\"\"$ s rule : Solutions of the system of equations $\"\"$ , $\"\"$ and $\"\"$ for $\"\"$ .

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Find the cost of the gaming plan $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Cost of the gaming plan $\"\"$ . \ \

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Find cost of the call plan $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Cost of the call plan $\"\"$ .

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Find cost of the messaging plan $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Cost of the messaging plan $\"\"$ .

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$\"\"$

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Cost of the gaming plan $\"\"$ . \ \

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Cost of the call plan $\"\"$ .

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Cost of the messaging plan $\"\"$ .