Ответ:
17
Пошаговое объяснение:
CA = (1-(-1), -4-(-3)) = (2, -1)
DB = (3-(-2), 2-3) = (5, -1)
CA + DB = (2+5, -1-1) = (7, -2)
BC = (-1-3, -3-2) = (-4, -5)
AD = (-2-1, 3-(-4)) = (-3, 7)
BC - AD = (-4-(-3), -5-7) = (-1, -12)
(CA + DB)(BC - AD) = 7 * (-1) + (-2) * (-12) = -7 + 24 = 17
Нет, не лежит т.к.
АВ=АС+СВ
АВ=3+7=10
10≠8
Ответ будет 96 в этом задании
AB = (1-(-2), -2-3, 3-1) = (3,-5,2)
BC = (4-1, -1-(-2), 0-3) = (3,1,-3)
2AB+3BC = 2*(3,-5,2) + 3*(3,1,-3) = (6,-10,4) + (9,3,-9) = (15,-7,-5)
|2AB+3AB| = sqrt (225 + 49 + 25) = sqrt (299)