Question

PLEASEE HELP ME, ITS JUST ONE PROBLEM, PLEASE HELPPPP <3<3 !!!

Answer 1

We can see that the function passes through the point $(2,-1)$. This implies that

$\log_b(2)=-1$

or, equivalently,

$b^{-1}=2 \iff \dfrac{1}{b}=2 \iff b=\dfrac{1}{2}$

The same conclusion could have been reached by observing that the function passes through $\left(\frac{1}{2},1\right)$