Skip to main content
Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 2, Problem 58

Solve each equation. √(4x+1)-√(x-1)=2

Verified step by step guidance
1
Identify the equation given: \(\sqrt{4x+1} - \sqrt{x-1} = 2\). Our goal is to solve for \(x\).
Isolate one of the square root terms to one side of the equation. For example, add \(\sqrt{x-1}\) to both sides to get \(\sqrt{4x+1} = 2 + \sqrt{x-1}\).
Square both sides of the equation to eliminate the square root on the left. This gives: \(\left(\sqrt{4x+1}\right)^2 = \left(2 + \sqrt{x-1}\right)^2\).
Simplify both sides: the left side becomes \$4x + 1\(, and the right side expands using the formula \)(a+b)^2 = a^2 + 2ab + b^2$ to \(4 + 4\sqrt{x-1} + (x - 1)\).
Rearrange the equation to isolate the remaining square root term, then square both sides again to eliminate it. After that, solve the resulting polynomial equation for \(x\), and check all solutions in the original equation to avoid extraneous roots.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
8m
Was this helpful?

Key Concepts

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

Square Root Functions and Radicals

Square root functions involve expressions under a radical sign (√). Understanding how to manipulate and simplify radicals is essential, especially when isolating terms or combining like radicals in an equation.
Recommended video:
02:20
Imaginary Roots with the Square Root Property

Isolating and Squaring Both Sides

To solve equations with square roots, isolate one radical on one side and then square both sides to eliminate the square root. This process may need to be repeated if multiple radicals remain, but it can introduce extraneous solutions.
Recommended video:
03:42
Linear Inequalities with Fractions & Variables on Both Sides

Checking for Extraneous Solutions

After solving, substitute solutions back into the original equation to verify their validity. Squaring both sides can create extraneous solutions that do not satisfy the original equation, so this step ensures only true solutions are accepted.
Recommended video:
05:21
Restrictions on Rational Equations