If log₁₀(100001 − 4^x)/(5 − x) = 1, then what is x equal to?

Given log₁₀(100001 − 4^x)/(5 − x) = 1, so log₁₀(100001 − 4^x) = 5 − x. Thus 100001 − 4^x = 10^(5−x) = 100000/10^x. For x = 0: 100001 − 1 = 100000 ✓ and 10^(5−0) = 100000 ✓. So x = 0.