<span>(-x-5)^2 - x(x+3) =39
х</span>²+10х+25-х²-3х=39
7х+25=39
7х=14
х=2
X^3 (x + 1) - 8(x + 1) = 0
(x^3 - 8) * ( x + 1) = 0
x^3 = 8
x = ∛8
<u>x = 2 </u>
x + 1 = 0
<u>x = - 1 </u>
Всё ))
2sinx*cosx+2cos^2x-2sin^2x=sin^2x+2cos^2x, -3sin^2x+2sinx*cosx+cos^2x=0, разделим все н (-cos^2x), 3tg^2x-2tgx-1=0, tgx=a, 3a^2-2a-1=0, a1=1, a2=-1/3. tgx=1, x=п/4+пk,kєZ, tgx=-1/3, x= -arctg(1/3)+nl, lєZ.