is 2.570*10 9 the correct way to express 2,570,000,000,000 in engineering notation
In scientific notation, 2,570,000,000,000 would be written as 2.57 x 1012
This is also correct for engineering notation since the power is divisible by 3. Don't forget that the number that starts the expression needs to be between 1 and 10 (2.57 here).
Hope this helps!