Question

первый вариант 3 и 4

Answer 1

$4.\log_{0,2}((x-2)(x+2)) leq log_{0,2}5\ x^2-4 geq 5\ x^2 geq 9\ xin(-infty;-3]U[3;+infty)$

$3.\ 5^{2x+1}+4*5^x-1=0\ 5*5^{2x}+4*5^x-1=0\ D=16+20=36\ 5^x= frac{-4-6}{10} =-1 textless 0\ 5^x= frac{-4+6}{10} = 5^{-1}\ x=-1$