Question

Матричное неравенство

Answer 1

$1); ; left|begin{array}{cc}1&x+5\2&xend{array}right|<0\\x-2(x+5)<0; ,; ; ; x-2x-10<0; ,; ; ; -x<10; ,; ; underline {x>-10}$

$2); ; left|begin{array}{ccc}2&x+2&-1\1&1&-2\5&-3&xend{array}right|>0\\2, (x-6)-(x+2)(x+10)-(-3-5)>0\\2x-6-(x^2+12x+20)+8>0\\-x^2-10x-18>0\\x^2+10x+18<0\\D/4=5^2-18=7; ,; ; x_{1,2}=-5pm sqrt7; ; to \\(x+5+sqrt7))(x+5-sqrt7)<0\\znaki:; ; ; +++(-5-sqrt7)---(-5+sqrt7)+++\\xin (-5-sqrt7, ;, -5+sqrt7)$