33*3=99
44*4=176
55*5=275
27/9=3
90/9=10
72/9=8
50*20=1 000
60*5=300
70*3=210
8*8=64
63/9=7
200*200*400=16 000 000
Sп.п. = 6*11^{2} = 726 см^{2}
Summ = 11*12=132 см
D = b² - 4ac
D = (-7)² - 4·1·12 = 49-48 = 1
2х - 7 = х + 2
2х - х = 2 + 7
х = 9
Проверка:
2 х 9 - 7 = 9 + 2
18 - 7 = 11
11 = 11