Question

What is the difference? StartFraction 2 x + 5 Over x squared minus 3 x EndFraction minus StartFraction 3 x + 5 Over x cubed minus 9 x EndFraction minus StartFraction x + 1 Over x squared minus 9 EndFraction StartFraction (x + 5) (x + 2) Over x cubed minus 9 x EndFraction StartFraction (x + 5) (x + 4) Over x cubed minus 9 x EndFraction StartFraction negative 2 x + 11 Over x cubed minus 12 x minus 9 EndFraction StartFraction 3 (x + 2) Over x squared minus 3 x EndFraction

Answer 1

Answer:

A. StartFraction (x + 5) (x + 2) Over x cubed minus 9 x EndFraction

Step-by-step explanation:

Given:

(2x + 5) / (x² - 3x) - (3x + 5) / (x³ - 9x) - (x + 1) / x² - 9

Factor the denominators

(2x + 5) / x(x - 3) - (3x + 5) / x(x - 3)(x + 3) - (x + 1) / (x - 3)(x + 3)

Lowest common multiple of the 3 fractions is x(x - 3)(x + 3)

= (2x+5)(x+3) - (3x + 5) - (x + 1)x / x(x - 3)(x + 3)

= (2x²+6x+5x+15) - (3x + 5) - (x² + x) / x(x - 3)(x + 3)

= 2x² + 11x + 15 - 3x - 5 - x² - x / x(x - 3)(x + 3)

= x² + 7x + 10 / x(x - 3)(x + 3)

Solve the numerator.

Solve the quadratic expression by finding two numbers whose product is 10 and sum is 7

The numbers are 5 and 2

= x² + 5x + 2x + 10 / x(x - 3)(x + 3)

= x(x + 5) + 2(x + 5) / x(x - 3)(x + 3)

= (x + 5)(x + 2) / x(x - 3)(x + 3)

A. StartFraction (x + 5) (x + 2) Over x cubed minus 9 x EndFraction

Recall,

x(x - 3)(x + 3) is a factor of x³ - 8x

A. StartFraction (x + 5) (x + 2) Over x cubed minus 9 x EndFraction

(x + 5)(x + 2) / x³ - 9x

B. StartFraction (x + 5) (x + 4) Over x cubed minus 9 x EndFraction

(x + 5)(x + 4) / x³ - 9x

C. StartFraction negative 2 x + 11 Over x cubed minus 12 x minus 9 EndFraction

2x + 11 / x³ - 12x - 9

D. StartFraction 3 (x + 2) Over x squared minus 3 x EndFraction

3(x + 2) / x² - 3x