(3/x)²-3=0
9/x²=3
x²=3
x=√3, x=-√3
5sin^2x+5sinxcosx-3sin^2x-3cos^2x=0
2sin^2x-3cos^2x+5sinxcosx=0
2tg^2x-3+5tgx=0
tgx=1/2 x=arctg(1/2)+Пk
tgx=-3 x=arctg(-3)+Пk
Правильно
36z² - 7z + d = 36z² - 7z + 49/144 = (6z)² - 2 * 6z * 7/12 + (7/12)² =
= (6z - 7/12)²