(1,2times 10^-5)/(6times 10^-2)-0,9times 10^9

To solve this expression, we need to perform the division first and then subtract the second term.Given expression: Step 1: Perform the division. Step 2: Subtract the second term. Since the exponents are different, it's easier to convert them to the same exponent: Now, subtract the two terms: Therefore, the correct answer is .