[" (a) "x+y+z],[" The solution of the equation "log_(2)log_(5)(sqrt(x^(2)+5+x))=0],[[" (a) "x=2," (b) "x=3]" (c) "xyzquad " (d) "x=-2],[" The number of real values of the parameter "k" for which "(bg_(1c)x)^(2)" - "bg_(1i)x^(2)+(1+z)^(-1)" (c) "x" it these "]