Answer:
9 Superscript negative 3
Step-by-step explanation:

300 - 297 = 3
294 - 291 = 3
288 - 285 = 3
So, that is a sequence of sums of number 3: 3 + 3 + 3 + .... + 3
How may times will the number 3 be added?
Note that 300 is reduced in 6 units each time => 300 / 6 = 50 => 3 will be added 50 times.
=> 50 * 3 = 150
Answer: 150
The wrong step is step 4, because you only need one conversion.
The formula to convers pounds to kilograms is

Obviously, the inverse formula is

So, you're given an input of 142 pounds. To convert it in kilograms, plug that value into out formula:

and this is the answer you're looking for, so you need no more steps.