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Ch. 1 - Equations and Inequalities
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 2, Problem 66

Solve each equation. (√x)+2=√(4+7√x)

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1
Start by rewriting the equation to clearly identify the expressions under the square roots: \(\sqrt{x} + 2 = \sqrt{4 + 7\sqrt{x}}\).
Isolate one of the square root terms if possible. In this case, both sides already have square roots, so the next step is to square both sides to eliminate the square roots. This gives: \((\sqrt{x} + 2)^2 = (\sqrt{4 + 7\sqrt{x}})^2\).
Expand the left side using the formula \((a + b)^2 = a^2 + 2ab + b^2\): \(x + 4\sqrt{x} + 4 = 4 + 7\sqrt{x}\).
Simplify the equation by subtracting 4 from both sides: \(x + 4\sqrt{x} = 7\sqrt{x}\).
Rearrange the terms to isolate \(x\) and \(\sqrt{x}\) on one side: \(x + 4\sqrt{x} - 7\sqrt{x} = 0\), which simplifies to \(x - 3\sqrt{x} = 0\). From here, you can proceed by substituting \(t = \sqrt{x}\) to solve the resulting equation.

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Key Concepts

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

Square Roots and Radicals

Square roots represent a value that, when multiplied by itself, gives the original number. Understanding how to manipulate and simplify expressions involving square roots is essential, especially when they appear on both sides of an equation.
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Isolating Variables in Radical Equations

To solve equations with radicals, it is important to isolate the radical expression before squaring both sides. This helps eliminate the square root and simplifies the equation, but care must be taken to check for extraneous solutions.
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Checking for Extraneous Solutions

Squaring both sides of an equation can introduce solutions that do not satisfy the original equation. After solving, substitute the solutions back into the original equation to verify which are valid.
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