(a-9)(a+1)-(a+8)(a+3) при a=-1/3

Question

(a-9)(a+1)-(a+8)(a+3) при a=-1/3

Answer 1

A^2 + a - 9a - 9 - (a^2 + 3a + 8a + 24) = 
= a^2 - 8a - 9 - (a^2 + 11a + 24) = 
= a^2 - 8a - 9 - a^2 - 11a - 24 = 
= - 19a - 33

- 19*(-1/3) - 33 = 19/3 - 33 = - 80/3 = - 26 целых  2/3