A) 6k+8=3k-13 ↔ 6k-3k=-13-8 ↔ 3k=-21 ↔ k= -7.
b) 6t+9=3(15+4t) ↔ 6t+9=45+12t ↔ 6t-12t=45-9 ↔ -6t= 36 ↔ t=-6.
c) 5y=8(y+3) ↔ 5y-8y= 24 ↔ -3y=24 ↔ y=-8.
41%=83
100%=?
83/41*100=сам решай
(Sin³x/Cos³x + Cos³x/Cos³x) / ( Sin³x/Cos³x - Cos³x/Cos³x) =
= (tg³x + 1) / ( tg³x - 1) = (2³ + 1) / ( 2³ - 1) = 9/7 = (1)2/7
1/2^x+1=x^2-4x+4
1/2^x=x^2-4x+3