<span>(а+4)×а+6/а^2-16×а-6/а-4
a(a+4)-16a-4-6/а+6^2/a^2
(a^4-12a^3-4a^2-6a+6)/а^2</span>
А) ...
sin^2 t - 2 sin t * cos^2 t = 1- sin 2t
1- sin 2t = 1- sin 2t
б) ...
<span>2 cos^2 t = 1+ cos^2 t - sin^2 t </span>
2 cos^2 t= sin^2 t +cos^2 t - cos^2 t - sin^2 (синусы сокращаются)
<span>2 cos^2 t = 2 cos^2 t</span>
1)(a+2b)^ 3
2)(3m-n)^ 3
3)(2p-3q)^ 3
4) (xy+2)^ 3
(5a-3)/(a+1) = a/(a-2) ОДЗ: a != -1 и a != 2.
(5a-3)(a-2) = a(a+1)
5a^2 - 13a + 6 = a^2 + a
4a^2 - 14a + 6 = 0
2a^2 - 7a + 3 = 0
D = 49 - 4*3*2 = 25
a = (7 +- 5)/4 => a = 3; 0,5.
Ответ: при a = 3 или 0,5.