Log10 x=-2 find x

If your question means:

log₍ ₁₀ ₎ ( x ) = - 2

then

The logarithm of a number is the exponent with which you need to scale the base to get that number.

In this case:

x = 10 ⁻ ² = 1 / 10 ² = 1 / 100 = 0.01

Log10 x=-2

10^-2=x
x=1/100=0.01