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Sum

**Evaluate :**

−7x^{2} + 18x^{2} + 3x^{2 }− 5x^{2}

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#### Solution

−7x^{2} + 18x^{2} + 3x^{2 }− 5x^{2}

= 21x^{2} − 12x^{2}

= 9x^{2}

Concept: Combining like Terms

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