<span>Anna learns in her science class that the human eye blinks an average of 4,200,000 times a year. What is this number expressed in scientific notation?</span>
Firstly, you've got to expand the brackets, this becomes;
8a-4= -10a+ 50
You've then got to eliminate the -10a and you do this by adding 10a to both sides,
This then becomes 18a-4=50
You've then got to add 4, to eliminate this, which then becomes 18a=54
You've then got to divide both sides by 18, and this becomes 3.
Therefor, a=3
Hope this helps :)
Answer:
I think it's B or C but I'm not sure cuz I'm struggling with this question also
