Which of the following is the simplified form of x plus 4 over 2 x plus 6 plus the fraction 3 over x squared minus 9 ?
\[\frac{ x - 4 }{ 2x + 6 } + \frac{ 3 }{ ?x^2 - 9}\]
\[\frac{x+4}{2x+6}+\frac{3}{x^2-9}\]?
Oops, there's a question mark in there, and it shouldn't be there
is x-4 or x+4?
in any case, start by factoring everything as much as possible, then make a common denominator for the two fractions so you can combine them
x-4
okay, because your problem statement says "x plus 4"
I'm sorry, it is x+4
I got this far: \[\frac{ x+4 }{ 2(x+3) } + \frac{ 3 }{ (x-3)(x+3) }\]
okay, to make the common denominator you'll have to multiply the lh fraction by (x-3)/(x-3) and the rh fraction by 2/2
do you see why?
yes
good. have fun :-)
is it: \[\frac{ 6+(x+4) }{ 2(x+3) }\]
\[x + 2 \over 2(x + 3)\] \[ x - 2 \over 2(x - 3) \] \[ x - 2 \over 2(x +3)\] \[ x+ 2 \over 2(x- 3) \]
Hmm, looks like you went off the rails somewhere... \[\frac{ x+4 }{ 2(x+3) } + \frac{ 3 }{ (x-3)(x+3) } = \frac{(x+4)} {2(x+3)}*\frac{(x-3)}{(x-3)} + \frac{3}{(x-3)(x+3)}*\frac{2}{2}\]\[=\frac{(x+4)(x-3) + 3*2}{2(x-3)(x+3) } = \frac{ x^2-3x+4x-12+6}{2(x-3)(x+3) }=\frac{x^2+x-6} {2(x-3)(x+3)}\]Now we factor the numerator, cancel common factors and we're done.
Its adding not multiplication
You have to multiply to get the common denominator in order to add
just like adding 1/4 and 1/7
\[\frac{1}{4} + \frac{1}{7} = \frac{1}{4}*\frac{7}{7} + \frac{1}{7}*\frac{4}{4} = \frac{7}{28} + \frac{4}{28} = \frac{11}{28}\]
But it has to be simplified so the (x-3)s would cancel each other, leaving: 6+(x+4)/2(x+3)
you're doing it wrong. what do you get when you factor \(x^2+x-6\)?
Join our real-time social learning platform and learn together with your friends!