in form ax²+bx+c=0 if a=1 then take 1/2 of b and square it then add that to both sides then complete square the move constnat to left then sqrt both sides then minus whatever
x²-5x-4=0 a=1 so -5/2=-2.5, (-2.5)²=6.25 add that to both sides x²-5x+6.25-4=6.25 factor perfect square (x-2.5)²-4=6.25 add 4 to both sides (x-2.5)²=10.25 sqrt both sides x-2.5=+/-√10.25 add 2.5 to both sides x=2.5+/-√10.25 to get into the answer form times left side by 2/2 [tex]x= \frac{5+/-2 \sqrt{10.25} }{2} [/tex] [tex]x= \frac{5+/- \sqrt{4*10.25} }{2} [/tex] [tex]x= \frac{5+/- \sqrt{41} }{2} [/tex]
