B² и b²<span> сокращаются. с</span>² :с= с²⁻¹=с
Ответ:2ас
(5x + y)² - (x - 5y)² = (5x + y - x + 5y)(5x + y + x - 5y) = (4x + 6y)(6x - 4y)
Как-то так.................
tg(180+b)=tgb=sinb/cosb cos(180-b)=-cosb tg(270+b)=-ctgb=-cosb/sinb
cos(270+b)=sinb tg(900-b)=(tg900+tgb)/(1-tg900tgb)=|tg900=tg(180+4п)=tg180=0|=tgb
<span> tg(180+b)cos(180-b)/tg(270+b)cos(270+b)+tg(900-b)=</span>
<span> sinb</span>
<span> - -------cosb</span>
<span> cosb sinb</span>
<span>----------------------- =------------------</span>
<span> cosb cosb-tgb</span>
<span>- ---------sinb+tgb</span>
<span> sinb</span>
Сразу решение:
= ( (2⁶)²/³ + (5³)¹/³ - (5⁴)¹/⁴) ¹/² =(2¹²/³ +5¹-5¹)¹/² =(2⁴)¹/²=2⁴/²=2²=4