3)
(33+47)²=80²=6400
(95-5)² = 90 ² = 8100
(41+11)(41-11)=52*30=1560
(59,5+39,5)(59,5-39,5)=99*20 = 1980
4)
х²-121=0
х²=121
х=√121
х=11
х=-11
х²+26х+169=0
(х+13)²=0
х+13=0
х=-13
х²-28х+196=0
(х-14)²=0
х-14=0
х=14
5)
а) =6²-(p²-2pt+t²) = 6² - (p-t)² = (6-p+t)*(6+p-t)