3/4+(5/8+t)=22/24+21/24
3/4+(5/8+ t)=43/24
5/8+ t=43/24-3/4
5/8+ t=43/24-18/24
5/8+ t=25/24
t=25/24-5/8
t=25/24-15/24
t=10/24
t=5/12
1)f'(x)=6x^2-sinx
2)f'(x)=tgx+x*(sinx/cosx)'=tgx+x/cos^2(x)=tgx+x*sec(x)=tgx+x*(1+tg^2(x))=x*tg^2(x)+tgx+x
2000:40=50+70=120•5=600-480. 72900-900=72000:800=90•30=2700-2000=700. 56000:700=80+120=200•60=12000:4000=3