ShirokovP

Verified answer

30a - 5*(a + 3)^2 = 30a - 5 *(a^2 + 6a + 9) = 
= 30a - 5a^2 - 30a - 45 = 
= - 5a^2 - 45 =
 
Затем
 - 5*(√3)^2 - 45  = - 5*3 - 45 = - 15 - 45 = - 60