log2(x-1)=-3 Wyznacz x

[latex] 2^{-3} [/latex]=(x-1) [latex] 2^{-3} [/latex]=[latex] frac{1}{8} [/latex] [latex] frac{1}{8} [/latex]=x-1 x=1[latex] frac{1}{8} [/latex]

2x-2=-3     /+2 2x=-1 x=-1/2