-3x-1=0 -3x=0+1 -3x=1 x=-1/3
1) 3a²b-ab²
2) 2x²-x-3
3) 19a-8b-3c-6d
4)7a²b²-3abкуб+2a в четвертой
16x + 15x^2 - 15=0
Преобразуем:
15x^2 +16x - 15 = 0
D = d^ - 4ac = 16^2 + 4*15*(-15) = 256 + 900 = 1156
1)Sin7αCos4α +Sin4αCos7α -3Sin11α = Sin11α - 3Sin11α = -2Sin11α
2)S<span>in2xCos3x-2Sin5x+Cos2xsin3x=Sin5x -2Sin5x = -Sin5x
3)C</span><span>os2,5xCos1,5x+Cosx+Sin1,5xSin2,5x= Cosx +Cosx = 2Cosx
4)</span><span>2(cos4x•cos7x+sin2x)+2•sin4x•sin7x=
=2Cos4xCos7x +4Sin2x +2Sin4xSin7x =
=2(Cos4xCos7x +Sin4xSin7x) +4Sin2x = 2Cos3x + 4Sin4x</span>