Question 629878
{{{x^2-3x-4=0}}}
Use the formula {{{a^2-2ab+b^2=(a-b)^2}}}
{{{x^2-3x-4=(x^2-2*x*(3/2)+(3/2)^2)-(3/2)^2-4=(x-3/2)^2-25/4}}}
{{{(x-3/2)^2-25/4=0}}}
{{{(x-3/2)^2=25/4}}}
{{{x-3/2=5/2}}}  or  {{{x-3/2=-5/2}}}
{{{x=4}}} or  {{{x=-1}}}
Answer: -1, 4