Question

(x)/(x^2+9x+20) - 4/(x^2+7x+12)

subtracting rational expressions

Answer 1

idk why but i get x+20 / (x+3) (x+4) (x+5)

Answer 2

\[\implies \frac{x}{(x+5)(x+4)} - \frac{4}{(x+4)(x+3)}\]
so LCD is (x+5)(x+4)(x+3)
\[\implies \frac{x(x+3) - 4(x+5)}{(x+5)(x+4)(x+3)}\]
\[\implies \frac{x^2 + 3x - 4x - 20}{(x+5)(x+4)(x+3)}\]
\[\implies \frac{x^2 - x - 20}{(x+5)(x+4)(x+3)}\]
\[\implies \frac{(x-5)(x+4)}{(x+5)(x+4)(x+3)}\]
does that give you an idea what to next?

Answer 3

how did u get the (x-5) (x+4) on the numerator on the last step?

Answer 4

wouldnt it be (x-20) since u combine like terms and subtract x from x^2 which gave us x-20

Answer 5

you cant subtract x from x^2

Answer 6

x^2 and x are different terms

Answer 7

oh ok

Answer 8

so x^2 - x -20 stays that way

Answer 9

then factor it out becomes (x-5)(x+4)

Answer 10

ohhhhhhhhh

Answer 11

thanks

Answer 12

welcome ^_^

Answer 13

well i need to go now so i hope you can proceed on your own :D

Answer 14

yes thank u so much!!

Answer 15

wonderful