To solve the equation \( 5 - 2x^2 = -15 \) using inverse operations, we will isolate \( x^2 \) step by step. Let's proceed:
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Subtract 5 from both sides: \[ 5 - 2x^2 - 5 = -15 - 5 \] This simplifies to: \[ -2x^2 = -20 \]
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Divide both sides by -2: \[ \frac{-2x^2}{-2} = \frac{-20}{-2} \] This simplifies to: \[ x^2 = 10 \]
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Take the square root of both sides: Remember to consider both the positive and negative roots. \[ x = \pm \sqrt{10} \] Thus, the solutions are: \[ x = \sqrt{10} \quad \text{and} \quad x = -\sqrt{10} \]
Now, let's check the solutions by substituting \( x \) back into the original equation.
Checking the solutions
For \( x = \sqrt{10} \): \[ 5 - 2(\sqrt{10})^2 = 5 - 2(10) = 5 - 20 = -15 \]
For \( x = -\sqrt{10} \): \[ 5 - 2(-\sqrt{10})^2 = 5 - 2(10) = 5 - 20 = -15 \]
In both cases, we find that the original equation holds true.
Final Answer
The solutions to the equation \( 5 - 2x^2 = -15 \) are: \[ \boxed{\sqrt{10}} \quad \text{and} \quad \boxed{-\sqrt{10}} \]