Mathematics

HELP!!!!  multiply and simplify  r⁴-16/r⁴-81·r²+9/r²+4 simplified product is ______


Answers

Quan336

4 years ago Comment

Best answer

[latex] \frac{ r^{4} -16}{ r^{4} -81}* \frac{ r^{2}+9 }{ r^{2}+4 } [/latex]

ok the best way to look at this is by factoring out so look at "r^4-16" if you factor out you get (r²-4)(r²+4) and the same with "r^4-81" if you factor out you get (r²-9)(r²+9) 

so now your problem looks something like this. 
[latex] \frac{( r^{2} -4)( r^{2} +4)( r^{2} +9)}{( r^{2} -9)( r^{2} +9)( r^{2} +4)} [/latex]

now cancel out like terms remember  [latex] \frac{ab}{bc}= \frac{a}{c} [/latex] because b/b=1

so now your left with [latex] \frac{( r^{2} -4)}{ r^{2} -9} [/latex]

lisaacervante

4 years ago Comment

Well, even this expression given by 'secretlyblu' can be factorized:
[latex]\frac{r^2-4}{r^2-9} = \frac{(r+2)(r-2)}{(r+3)(r-3)} [/latex]