2x^2 - 16x = x(2x-16)

 x^2 - 2x - 80 = x(x-2-80/x)

3x^2 - 147 = x(3x-147/x)

5r^2 - 39r - 8 = r(5r-39-8/r)

7b^2 + 37b + 10 = b(7b+37+10/b)

6n^2 + 5n - 6 = n(6n+5-6/n)

 Please try Algebrator for these types of problems:

Windows: http://www.softmath.com/tr/alg51win-tr-en.exe

Mac: http://www.softmath.com/tr/alg51mac-tr-en.dmg

and for the documentation, you may wish to use this link (the contents of this document are also available through the Manual Button):

http://www.algebrasolver.com/AlgebratorManual_50.pdf