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Solve the equation 4y squared equal to 100 using the Square Root Property.
Ay = 25 and y = -25
By = 5 and y = -5
Cy = 5 and y = 0
Dy = 10 and y = -10
Answer & Solution
Correct answer: B. y = 5 and y = -5
1. The Square Root Property needs the squared term alone with a coefficient of one.
2. Divide both sides by 4 to make that happen.
3. The left side becomes y squared and the right side becomes 100 divided by 4.
4. That gives y squared equal to 25.
5. Take the square root of both sides, keeping both the positive and negative roots.
6. The square root of 25 is 5, so the solutions are 5 and negative 5.
7. The pair 25 and negative 25 stops before taking the square root.
8. The pair 5 and 0 keeps the positive root but invents a second root of 0.
9. The pair 10 and negative 10 takes the root of 100 without dividing by 4 first.
_Source: OpenStax Intermediate Algebra (CC BY 4.0), section 9.1 Solve Quadratic Equations Using the Square Root Property_