What is the LCD of this problem and the solution? (x+5)/(x^2+7x+12) + (x^2+8x+15)/(X^2+4x+3)

Expert Answers
embizze eNotes educator| Certified Educator

Simplify `(x+5)/(x^2+7x+12)+(x^2+8x+15)/(x^2+4x+3)` :

To add rational expressions, like fractions, we need to find a common denominator. The best is the least common multiple of the denominators. The easiest way to find the LCM is to factor:



The LCM/LCD has every factor that appears in the factored forms to the highest degree that it appears. So the LCD is (x+3)(x+4)(x+1).





Now the rational expressions have a common denominator so add the numerators: