How do you find solutions for this linear function A(x)=9x^2-25/3x +5?

Question

hartnn · Answer

can u factorize  9x^2-25 ? 
do u realise its the difference of squares?

anonymous · Answer

I'm really not sure what I'm doing I don't remember any of this

hartnn · Answer

u remember/note this : 
$\huge a^2-b^2 = (a+b)(a-b)$
now write 
$\huge 9x^2 = (3x)^2 $
and how will be 25 written as ?

anonymous · Answer

25^2=5^2?

hartnn · Answer

yes, correct!
now apply that formula and tell me what u get on right side ?

anonymous · Answer

25^2-5^2=625-25=600?

hartnn · Answer

where does 25 come from ?? 
$\huge (3x)^2-5^2 = (...)(...)$
how will u fill up those brackets using the formula i gave

anonymous · Answer

(3x^2+5^2) and (3x^2-5^2)?

hartnn · Answer

no!
write a= 3x and b=5
now tell me what u get

anonymous · Answer

Oh you don't put the squares?

hartnn · Answer

no, the right side of formula does not have squares, thats y don't put

anonymous · Answer

Oh okay sorry I'm really bad at this stuff I'm suppose to do the (a+b) (a-b) though right?

hartnn · Answer

yes

anonymous · Answer

So it's just (3+5) and (3-5)?

hartnn · Answer

where did x disappear ? 
it will be 
$\huge (3x)^2-5^2= (3x+5)(3x-5)$
got this ?

hartnn · Answer

then simplifying this will be easy 
$\large A(x)=\frac{ A(x)=9x^2-25}{3x+5}=\frac{(3x+5)(3x-5)}{3x+5}=?$