Hi,
a) (3x+1)2+(4x-1)2=(3x+2)2+2(9x-1)
9x2+6x+1 + 16x2-8x+1 = 9x2+12x+4 = 18x-2
16x2-32x = 0
16x(x-2) = 0
x1 = 0 und x2 = 2
b) (6x-1)2- 25(x+1)2= (2x-5)2
36x2-12x+1 - 25(x2+2x+1) = 4x2-20x+25
36x2-12x+1 - 25x2-50x-25 = 4x2-20x+25
7x2-42x-49 = 0 |:7, dann pq-Formel
x1 = -1 und x2 = 7
Grüße