Question 201277
{{{b^4+13b^2+36=0}}}
{{{(b^2+9)(b^2+4)=0}}}
{{{(b+3i)(b-3i)(b+2i)(b-2i)=0}}}
b = 3i, -3i, 2i, -2i
http://www77.wolframalpha.com/input/?i=+b^4%2B13b^2%2B36%3D0

{{{-3x^2-2x-5=0}}}
Use this URL --> http://www.algebra.com/algebra/homework/quadratic/quadratic.solver
*[invoke quadratic "x", -3, -2, -5]
{{{(-3x+5)(x-1)=0}}}
x=5/3 and 1


{{{9m^2+16=24mn}}}
{{{9m^2-24mn+16=0}}}
I am guessing you left off an n^2
{{{9m^2-24mn+16n^2=0}}}
{{{(3m-4)(3m-4)=0}}}
m=4/3
http://www77.wolframalpha.com/input/?i=9x^2-24xy%2B16y^2%3D0