Question

If 10-10ˣ=9.9, find x

Answer 1

we are given

$10-10^x=9.9$

we can move 10 on right side

$-10^x=9.9-10$

$-10^x=-0.1$

we cancel -1

$10^x=0.1$

we can rewrite right side

$10^x=10^{-1}$

we can compare exponents

and we get

$x=-1$.............Answer