1) t²-10t+25 = (t-5)² = (t-5)(t-5)
2) х²-3х-10=0
D=9+40=49
х₁=3-7 / 2 = -2
х₂=3+7 / 2 = 5
х²-3х-10 = (х+2)(х-5)
3) 3х²-8х+5=0
D=64-60=4
х₁=8-2 / 6 = 4/6 = 2/3
х₂=8+2 / 6 = 10/6 = 1 2/3
3х²-8х+5=(х- 2/3)(х- 1 2/3)
4) 2х+6-х²=0
х²-2х-6=0
D=4+24 = 28
х₁ = 2-2√7 / 2 = 2(1-√7) / 2 = 1-√7
х₂ = 2+2√7 / 2 = 2(1+√7) / 2 = 1+√7
2х+6-х²=(х-1+√7)(х-1-√7)