Question

$( frac{1}{36} ) ^{x}-5*6^{-x} -6 leq 0$

Answer 1

6*(-x)=a
a²-5a-6≤0
a1+a2=5 U a1*a2=-6⇒a1=-1 U a2=6
-1≤a≤6
-1≤6^(-x)≤6
-x≤1
x≥-1
x∈[-1;∞)