-7/16 = -0.43751 241/990 = 1.273737373737...
A = (2a - b)² - (2a - b)(b + 2a) - 2b²= (2(-1/4) - 3)² - (2(-1/4) - 3)(3 + 2(-1/4)) - 23²= (-1/2 - 3)² - (-1/2 - 3)(3 - 1/2) - 18= (-7/2)² - (-7/2 * 5/2) - 18= 49/4 - (-35/4) - 18= 49/4 + 35/4 - 72= 84/4 - 72= 21 - 72= -51
Таким образом,A = -51.
-7/16 = -0.4375
1 241/990 = 1.273737373737...
A = (2a - b)² - (2a - b)(b + 2a) - 2b²
= (2(-1/4) - 3)² - (2(-1/4) - 3)(3 + 2(-1/4)) - 23²
= (-1/2 - 3)² - (-1/2 - 3)(3 - 1/2) - 18
= (-7/2)² - (-7/2 * 5/2) - 18
= 49/4 - (-35/4) - 18
= 49/4 + 35/4 - 72
= 84/4 - 72
= 21 - 72
= -51
Таким образом,
A = -51.