Posted by bob on Monday, December 13, 2010 at 8:22pm.
20xsquared+40 x+15=0

11th grade  chemistry, Sunday, January 9, 2011 at 3:01pm
factor out 5
u get
5(4x^2+8x +3) = 0
5(4x^2+2x+6x+3)=0
5(2x(2x+1)+3(2x+1))=0
5(2x+1)(2x+3)=0
x=1/2
or
x=3/2