(3+2x)^2​​ −3,6x(3x+4) при x=2,5

Question

(3+2x)^2​​ −3,6x(3x+4) при x=2,5

Answer 1

9+4x^2+12x-10.8x^2-14.4x=-6.8x^2+9-2.4x=>  x=2.5=>  -6.8*6.25+9-2.4*2.5=-33.5-6=-39.5

Answer 2

9 + 12x + 4x^2 - 10,8x^2 - 14,4x = - 6,8x^2  - 2,4x + 9
При x = 2,5:
- 6,8*6,25 - 6 + 9 = - 42,5 - 6 + 9 = - 48,5 + 9 = - 39,5
Ответ: - 39,5