Skip to main content
Ch. 1 - Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 2, Problem 16

Solve each equation in Exercises 15–34 by the square root property. 5x2=45 5x^2 = 45

Verified step by step guidance
1
Start with the given equation: \(5x^2 = 45\).
Divide both sides of the equation by 5 to isolate \(x^2\): \(x^2 = \frac{45}{5}\).
Simplify the right side: \(x^2 = 9\).
Apply the square root property, which states that if \(x^2 = a\), then \(x = \pm \sqrt{a}\): \(x = \pm \sqrt{9}\).
Simplify the square root to find the two possible values for \(x\).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Square Root Property

The square root property states that if x² = k, then x = ±√k. This method is used to solve quadratic equations that can be written in the form x² = a constant. It involves isolating the squared term and then taking the square root of both sides, remembering to include both positive and negative roots.
Recommended video:
02:20
Imaginary Roots with the Square Root Property

Isolating the Variable Term

Before applying the square root property, the equation must be manipulated so that the squared term stands alone on one side. This often involves dividing or multiplying both sides of the equation to simplify it. For example, dividing both sides of 5x² = 45 by 5 isolates x².
Recommended video:
Guided course
05:28
Equations with Two Variables

Simplifying Square Roots

After taking the square root of both sides, simplifying the radical expression is necessary. This includes factoring out perfect squares from under the root to write the answer in simplest form. For instance, √9 simplifies to 3, which makes the solution clearer and more exact.
Recommended video:
02:20
Imaginary Roots with the Square Root Property