Question

Which expression is equivalent to StartFraction 2 a + 1 Over 10 a minus 5 Endfraction divided by StartFraction 10 a Over 4 a squared minus 1 EndFraction?

Answer 1

Answer:

$\frac{(2a + 1)^2}{50a}$

Step-by-step explanation:

Given

$\frac{2a + 1}{10a - 5} / \frac{10a}{4a^2 - 1}$

Required

Find the equivalent

We start by changing the / to *

$\frac{2a + 1}{10a - 5} / \frac{10a}{4a^2 - 1}$

$\frac{2a + 1}{10a - 5} * \frac{4a^2 - 1}{10a}$

Factorize 10a - 5

$\frac{2a + 1}{5(2a - 1)} * \frac{4a^2 - 1}{10a}$

Expand 4a² - 1

$\frac{2a + 1}{5(2a - 1)} * \frac{(2a)^2 - 1}{10a}$

$\frac{2a + 1}{5(2a - 1)} * \frac{(2a)^2 - 1^2}{10a}$

Express (2a)² - 1² as a difference of two squares

Difference of two squares is such that: $a^2- b^2= (a+b)(a-b)$

The expression becomes

$\frac{2a + 1}{5(2a - 1)} * \frac{(2a - 1)(2a + 1)}{10a}$

Combine both fractions to form a single fraction

$\frac{(2a + 1)(2a - 1)(2a + 1)}{5(2a - 1)10a}$

Divide the numerator and denominator by 2a - 1

$\frac{(2a + 1)((2a + 1)}{5*10a}$

Simplify the numerator

$\frac{(2a + 1)^2}{5*10a}$

$\frac{(2a + 1)^2}{50a}$

Hence,

$\frac{2a + 1}{10a - 5} / \frac{10a}{4a^2 - 1}$ = $\frac{(2a + 1)^2}{50a}$