This is an extremely common question testing the applications of equations involving indices and sometimes logarithmic functions. Technique to approach this kind of question is to express the desired value (10^2x in this case) in a simpler form with smaller numbers (2 and 5 in this case). Work out the left side to reach (2^2x)(5^2x) through careful application of the law of induced. Check if my answer is correct when u return back to school.