Question

For the rational expression 2x^2-7x-15/x^2-25, do both of the following,

Answer 1

Answer:

a. $\frac{2x + 3}{x+5}$

b. x ≠ -5 (Vertical asymptote) and x ≠ 5 (Hole)

Step-by-step explanation:

Factor the numerator (Grouping):

$2x^2 - 7x - 15$              

Two numbers that multiply to -30 and add to -7 = -3 and 10

$[2x^2 - 10x] + [3x - 15]$

$(2x + 3)(x - 5)$

Factor the denominator (Difference of Two Squares):

$x^2 - 25$ = $(x +5)(x-5)$

Factored Expression:

(x - 5) can be factored out of top and bottom as a hole-

$\frac{(2x + 3)(x - 5)}{(x + 5)(x - 5)} = \frac{2x + 3}{x+5}$

Variable Restrictions:

Denominator ≠ 0

$x + 5 = 0\\x = -5$

Vertical asymptote at x = -5 ⇒ x ≠ -5