Question

Найдите значение выражения.


1) 8a ^ 2 * (a - 5) - 4a(a ^ 2 - 7) bunda a = 3

2) b(- 9b ^ 2 + 1) + 3b(2b ^ 2 + b) bunda b = - 2

3) (3x - 4)(8x + 2) - 24x ^ 2 - 2 bun * dax = 2

4) (c ^ 2 + 3)(c - 9) - c ^ 2 * (c - 6) bunda c = - 5​

Answer 1

Ответ:

1)8a ^ 2 * (a - 5) - 4a(a ^ 2 - 7) = 8a ^ 3 - 40a^2 - 4a^3 + 28a = 4a^3 - 40a^2 + 28a = 4*3^3 - 40*3^2 + 28*3= 108 - 360 + 84 = -168

2)b(- 9b ^ 2 + 1) + 3b(2b ^ 2 + b)= -9b^3 + b + 6b^3 +3b^2 = -3b^3 + 3b^2 + b = -3(-2)^3 + 3(-2)^2 + (-2) = -3*(-8) + 3*4 -2= 24 + 12 - 2 = 34

3) (3x - 4)(8x + 2) - 24x ^ 2 - 2 = 24x^2 + 6x - 32x - 8 - 24x^2 - 2 = -26x - 10 = -26*2 - 10 = -52 - 10 = - 62

4) (c ^ 2 + 3)(c - 9) - c ^ 2 * (c - 6) = c^3 - 9c^2 + 3c - 27 - c^3 + 6c^2 = -3c^2 + 3c - 27 = -3(-5)^2 +3*(-5) - 27 = -3*25 - 15 - 27 = -75 - 15 - 27 = -117