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

a. write the rational expression in factored form
b. state any restrictions on the variable

Respuesta :

Answer:

a. [tex]\frac{2x + 3}{x+5}[/tex]

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

Step-by-step explanation:

Factor the numerator (Grouping):

[tex]2x^2 - 7x - 15[/tex]              

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

[tex][2x^2 - 10x] + [3x - 15][/tex]

[tex](2x + 3)(x - 5)[/tex]

Factor the denominator (Difference of Two Squares):

[tex]x^2 - 25[/tex] = [tex](x +5)(x-5)[/tex]

Factored Expression:

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

[tex]\frac{(2x + 3)(x - 5)}{(x + 5)(x - 5)} = \frac{2x + 3}{x+5}[/tex]

Variable Restrictions:

Denominator ≠ 0

[tex]x + 5 = 0\\x = -5[/tex]

Vertical asymptote at x = -5 ⇒ x ≠ -5