Pls answer this. I don't understand

10^a is above 10^4 and in the next step that equals 1, so 10^a would need to be 10^4 because any number divided by itself equals 1.
Now if a is 4 then b needs to be 15-4 = 11
The answer is a = 4, b = 11
Answer:
The answer is a = 4, b = 11
Step-by-step explanation:
Now give that guy above brainliest!