Да степени плюсуются a^2×a^2=a^4
Y`=3*7x^6-15x+1/2√x=21x^6-15 +1/2√x
2) 5y/y-1 + 7y/2(y-1)= 10y+7y/2(y-1)=17y/2(y-1)
A = 1 - 2b
y = (1 - 2b)*b = b - 2b^2
y' = 1 - 4b
b = 1/4 - точка максимума
a = 1 - 2*(1/4) = 1 - (1/2) = 1/2
(1/2)*(1/4) = 1/8 - максимум a*b
1(тк 8х/8х=1)+1+3-8х =5-8х