x²-x=1
x²-x+1/4=1+1/4
(x-1/2)²=5/4
x-1/2=±√5/2
x=(1-√5)/2,x=(1+√5)/2
y²+5y=84
y²+5y+25/4=84+25/4
(y+5/2)²=361/4
y+5/2=±19/2
y=-12,y=7