Simplify sqrt(25x²)/sqrt(x²): Step-by-Step Radical Reduction

Solve the following exercise:

$\frac{\sqrt{25x^2}}{\sqrt{x^2}}=$

Express the definition of root as a power:

$\sqrt[n]{a}=a^{\frac{1}{n}}$

Remember that in a square root (also called "root to the power of 2") we don't write the root's power:

$n=2$

meaning:

$\sqrt{a}=\sqrt[2]{a}=a^{\frac{1}{2}}$

Proceed to convert the expression using the root definition we mentioned above:

$\frac{\sqrt{25x^2}}{\sqrt{x^2}}=\frac{(25x^2)^{\frac{1}{2}}}{(x^{2)^{\frac{1}{2}}}}$

Now let's recall two laws of exponents:

a. The law of exponents for a power applied to a product inside of parentheses:

$(a\cdot b)^n=a^n\cdot b^n$

b. The law of exponents for a power of a power:

$(a^m)^n=a^{m\cdot n}$

Let's apply these laws to the numerator and denominator of the fraction in the expression that we obtained in the last step:

$\frac{(25x^2)^{\frac{1}{2}}}{(x^{2)^{\frac{1}{2}}}}=\frac{25^{\frac{1}{2}}\cdot(x^2)^{\frac{1}{2}}}{(x^2)^{\frac{1}{2}}}=\frac{25^{\frac{1}{2}}x^{2\cdot\frac{1}{2}}}{x^{2\cdot\frac{1}{2}}}$

In the first stage we applied the above law of exponents mentioned in a' and then proceeded to apply the power to both factors of the product inside of the parentheses in the fraction's numerator.

We carried this out carefully by using parentheses given that one of the factors in the parentheses is already raised to a power. In the second stage we applied the second law of exponents mentioned in b' to the second factor in the product in the fraction's numerator and similarly to the factor in the fraction's denominator,

Let's simplify all of the expressions that we obtained:

$\frac{25^{\frac{1}{2}}x^{2\cdot\frac{1}{2}}}{x^{2\cdot\frac{1}{2}}}=\frac{\sqrt{25}x^{\frac{2}{2}}}{x^{\frac{2}{2}}}=\frac{5x^1}{x^1}$

In the first stage we converted the fraction's power back to a root. For the first factor in the product, this was done using the definition of root as a power mentioned at the beginning of the solution (in the opposite direction)

We then proceeded to calculate the numerical value of the root.

Additionally - we calculated the product of the power of the second factor in the product in the fraction's numerator in the expression that we obtained. Similarly we carried this out for the factor in the fraction's denominator. We then simplified the resulting fraction for that factor.

Let's complete the calculation and simplify the resulting fraction:

$\frac{5x^1}{x^1} =\frac{5\not{x}}{\not{x}}=5$

Let's summarize the steps of the solution thus far, as seen below:

$\frac{\sqrt{25x^2}}{\sqrt{x^2}}=\frac{(25x^2)^{\frac{1}{2}}}{(x^{2)^{\frac{1}{2}}}} =\frac{5x^1}{x^1} =5$

Therefore the correct answer is answer c.