(2log(7,x^2+6x))/(log(7,x^2))<=1
ОДЗ:
x^2+6x>0 => x C (-oo;-6) U (0;+oo)
x^2>0 => x=\=0
(2log(7,x^2+6x)-log(7,x^2))/log(7,x^2)<=0
2log(7,|(x^2+6x)/x| / (log(7,x^2)<=0
log(7,x^2)=0
x^2=1 => x=+-1
2log(7,|x+6|)=0
|x+6|=1 => x=-5; x=-7
методом интервалов, учитывая ОДЗ
ответ: [-7;-6) U (0;1)
79²+73²-49²-55²=(79²-55²)+(73²-49²)=(79-55)(79+55)+(73-49)(73+49)=24*134+24*122=24*(134+122)=24*256=6144