2(2x-13)²-6(2x-13)+4=0
(2x-13)²-3(2x-13)+2=0 |:2
2x - 13 = t
t²-3t+2=0
D = 9 - 8 = 1 дискриминант = 1 при замене
t12 = ( 3 +- 1)/2 = 1 2
1. 2x - 13 = 1
2x = 14
x = 7
2. 2x - 13 = 2
2x = 15
x = 7.5
ответ х = {7, 7.5} D = 1
