Please answer and EXPLAIN YOUR WORK I’ll mark brainliest

Aye asap pls ! markin da brainiest too ! btw da step choices are all add, distribute, divide, n subtract

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Which expression is equivalent to -12(3x-3/4)