1) x²+3x-4=0
x²+4x-x-4=0
x(x+4) -(x+4) =0
(x+4) (x-1) =0
x+4=0 x-1=0
x=-4 x=1
2) 25x²-10x+1=0
(5x-1) ²=0
5x-1=0
5x=1
x=1/5
1) x²+3x-4=0
x²+4x-x-4=0
x(x+4) -(x+4) =0
(x+4) (x-1) =0
x+4=0 x-1=0
x=-4 x=1
2) 25x²-10x+1=0
(5x-1) ²=0
5x-1=0
5x=1
x=1/5