Intermediate Algebra: Connecting Concepts through Application

Published by Brooks Cole
ISBN 10: 0-53449-636-9
ISBN 13: 978-0-53449-636-4

Chapter 4 - Quadratic Functions - Chapter Review Exercises - Page 400: 36

Answer

The solutions are $m = \frac{5}{2}$ and $m = -\frac{5}{2}$.

Work Step by Step

First, we can factor out what is common in the two terms: $2(4m^2 - 25) = 0$ We can simplify the equation by dividing each side by $2$: $4m^2 - 25 = 0$ We can see that this equation features the difference of two squares. To factor an equation in the form $a^2 - b^2 = 0$, we use the following formula: $a^2 - b^2 = (a - b)(a + b)$ Let's apply this formula to our equation, where $a = m$ and $b = 5$: $(m - 5)(m + 5) = 0$ According to the zero product property, if the product of two factors equals $0$, then either factor can be $0$; therefore, we can set each of these factors equal to $0$ and solve: $2m - 5 = 0$ or $2m + 5 = 0$ Let's look at the first factor: $2m - 5 = 0$ Add $5$ to both sides of the equation: $2m = 5$ Divide each side by $2$: $m = \frac{5}{2}$ Let's look at the second factor: $2m + 5 = 0$ Subtract $5$ from both sides of the equation: $2m = -5$ Divide each side by $2$: $m = -\frac{5}{2}$ The solutions are $m = \frac{5}{2}$ and $m = -\frac{5}{2}$. To check our answer, we substitute each of these values into the original equation to see if the two sides equal one another: $8(\frac{5}{2})^2 - 50 = 0$ Evaluate exponents first: $8(\frac{25}{4}) - 50 = 0$ Multiply: $\frac{200}{4} - 50 = 0$ Simplify the fraction: $50 - 50 = 0$ Subtract: $0 = 0$ The two sides of the equation are equal to one another; therefore, this solution is correct. Let's check the other solution: $8(-\frac{5}{2})^2 - 50 = 0$ Evaluate exponents first: $8(\frac{25}{4}) - 50 = 0$ Multiply: $\frac{200}{4} - 50 = 0$ Simplify the fraction: $50 - 50 = 0$ Subtract: $0 = 0$ The two sides of the equation are equal to one another; therefore, this solution is correct.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.