Problem 220 - Elementary Algebra

Question

In the following exercises, simplify. $$ \frac{3}{5} \sqrt{75}-\frac{1}{4} \sqrt{48} $$

Step-by-Step Solution

Answer

The simplified form is \( 2 \sqrt{3} \)

Step 1: Simplify the square roots

First, simplify the square roots. For \( \sqrt{75} \):\[ \sqrt{75} = \sqrt{25 \times 3} = \sqrt{25} \times \sqrt{3} = 5 \sqrt{3} \] For \( \sqrt{48} \):\[ \sqrt{48} = \sqrt{16 \times 3} = \sqrt{16} \times \sqrt{3} = 4 \sqrt{3} \]

Step 2: Substitute the simplified square roots back

Replace the simplified forms into the original expression: \[ \frac{3}{5} \sqrt{75} - \frac{1}{4} \sqrt{48} \Rightarrow \frac{3}{5} (5 \sqrt{3}) - \frac{1}{4} (4 \sqrt{3}) \]

Step 3: Simplify the coefficients

Simplify the coefficients in the expression: For the first term: \[ \frac{3}{5} \times 5 \sqrt{3} = 3 \sqrt{3} \] For the second term: \[ \frac{1}{4} \times 4 \sqrt{3} = \sqrt{3} \]

Step 4: Combine like terms

Combine the like terms: Subtract the simplified terms: \[ 3 \sqrt{3} - \sqrt{3} = (3-1) \sqrt{3} = 2 \sqrt{3} \]

Key Concepts

Square Roots

Square roots are a fundamental concept in mathematics. To put it simply, the square root of a number is a value that, when multiplied by itself, gives the original number. For instance, the square root of 25 is 5 because 5 multiplied by 5 equals 25. The notation for square root is denoted by the radical symbol ( \sqrt{} ). To illustrate this with an example from our exercise: \[ \sqrt{75} = \sqrt{25 \cdot 3} = \sqrt{25} \cdot \sqrt{3} = 5 \sqrt{3} \] Similarly for another example: \[ \sqrt{48} = \sqrt{16 \cdot 3} = \sqrt{16} \cdot \sqrt{3} = 4 \sqrt{3} \] In both examples, breaking down the number inside the square root into its prime factors helps simplify the expressions.

Simplifying Expressions

Simplifying expressions often involves making them as neat and as simple as possible. When dealing with radicals like square roots, this often means breaking down the radicand (the number inside the square root) into its factors. Then, we can simplify by taking the square roots of any perfect squares among those factors. Consider our exercise example: We began with \[ \frac{3}{5} \sqrt{75} - \frac{1}{4} \sqrt{48} \] By simplifying the square roots first, the expressions become more manageable: \[ \frac{3}{5} (5 \sqrt{3}) - \frac{1}{4} (4 \sqrt{3}) \] After breaking it down: \[ 3 \sqrt{3} - \sqrt{3} \] Simplifying coefficients also helps, as seen here where the coefficients of square roots get simplified: \[ 3 \times 5 = 3 \sqrt{3} \quad and \quad \frac{1}{4} \times 4 = \sqrt{3} \]

Algebraic Manipulation

Algebraic manipulation involves rearranging and simplifying algebraic expressions using various rules and properties. One essential skill is combining like terms, which means merging terms that contain the same variables or radicals. In our exercise: \[\begin{aligned} 3 \sqrt{3} - \sqrt{3} & = (3 - 1) \sqrt{3} \ & = 2 \sqrt{3} \end{aligned}\] This step-by-step approach shows how simplifying the terms individually and then combining them leads to a cleaner and easier final expression. Practice makes perfect with algebraic manipulation, as it requires familiarity with properties of numbers and operations. But mastering it is crucial for tackling more complex mathematical problems.