Question 99385
first, using multiplication or division, set the coefficient of the squared term to 1


2x^2-10x+5=0 ... dividing by 2 gives x^2-5x+(5/2)=0


next, using addition or subtraction, set the constant term to 0


x^2-5x+(5/2)=0 ... subtracting 5/2 gives x^2-5x=-5/2


next, take 1/2 of the coefficient of the first order term, square it, and add (to BOTH sides)


(-5/2)^2=25/4 ... x^2-5x+(25/4)=15/4


take the square root (positive AND negative) ... x-(5/2)=(sqrt(15))/2 and x-(5/2)=-(sqrt(15))/2


so {{{x=(5 +- sqrt(15))/2}}}