a² - 16b² a <span>- 4b</span>
-------------- : ( --------- )
4ab 4ab
( a - 4b ) <span>∙ ( a + 4b ) 4ab
------------------------------- </span><span><span>∙ ------------- = a +4b
</span> 4ab a - 4b
5 2 5 4 </span><span>∙ 44 44</span> + 176 220
3 ------ + 4 <span>∙ 4 </span>----- = 3 ----- + ----------- = --------------- = --------- =
13 13 13 13 13 13
12
= 16 ------
13
-pi/2<=5-2x<=pi/2 /// *(-1)
pi/2>=2x-5>=-pi/2 /// +5
pi/2+5>=2x>=-pi/2+5 /// :2
pi/4+2.5>=x>=-pi/4+2.5
Ответ: [-pi/4+2.5;pi/4+2.5]
<em />х + у = 4 * (- 2) -2х -2у = -8 у = - 5
2х - 3у = 13 2х - 3у = 13 2х - 3 * (-5) = 13
-2х - 2у + 2х - 3у = -8 + 13 2х + 15 = 13
-2у - 3у = 5 2х = 13 - 15
- 1у = 5 2х = - 2
у = 5 : ( - 1) х = -1
у = -5
Ответ: ( -1; -5)
Надеюсь правильно)))