Question 31035
ez enough, but check if i do sumthin wrong
4b(4b)-8b-5=0
{{{16b^2-8b-5=0}}} now factor adds up to -8 and multiplies to -80.  -10*8.  there fore the equation yields {{{16b^2+8b-10b-5}}} .  {{{16b^2+8b}}} has 8b in common, -10b-5 has -5 in common.  our new equation, factored once, is 
8b(2b+1)-5(2b+1) 
likes attract and: (8b-5)(2b+1)=0 thence one of the two (...) must equal zero, we don't know which, thence X=-.5 or 5/8

im me 4 questions.