Solve the following equations x^2-2x+4=0, x^2+4x+1=0

x²-2x+4= (x-2)(x-2)=0  x=-2 (double root)  

x²+5x+1=0

x_1,2= -5+_ (5²-4(1)(1) )^0.5/2 

x₁=4.8     x₂=-0.2 (to 1 d.p.)