Is this equation true?
a-b=a+(-b)

yes,it is true

Step-by-step explanation:

a-b=a+(-b)

a-b=a-b because positive and negative form negative (+,-)= -

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents