Question

Determine what must be multiplied so that the expression below will have a common denominator. Use the backslash / to type in a fraction.

Answer 1

Answer:

Multiply the first fraction by $\frac{x+4}{x+4}$

Multiply the second fraction by $\frac{x-4}{x-4}$

Step-by-step explanation:

Given

$\frac{4}{x^2 - 16} + \frac{3}{x^2 + 8x + 16}$

Required

Make the denominator equal

$\frac{4}{x^2 - 16} + \frac{3}{x^2 + 8x + 16}$

Factorize the denominator

$\frac{4}{x^2 - 4^2} + \frac{3}{x^2 + 4x + 4x+ 16}$

$\frac{4}{(x - 4)(x + 4)} + \frac{3}{(x+ 4)(x + 4)}$

Multiply the first fraction by $\frac{x+4}{x+4}$

Multiply the second fraction by $\frac{x-4}{x-4}$

$\frac{x+4}{x+4} * \frac{4}{(x - 4)(x + 4)} + \frac{3}{(x+ 4)(x + 4)} * \frac{x-4}{x-4}$

$\frac{4(x + 4)}{(x - 4)(x + 4)(x + 4)} + \frac{3(x - 4)}{(x+ 4)(x + 4)(x - 4))}$

$\frac{4(x + 4)}{(x^2 - 16)(x + 4)} + \frac{3(x - 4)}{(x^2 - 16)(x + 4))}$

The expression now have the same denominator