4 -9 -9
1 -3 - 6

I need hellp

This is different from the first one can someone me

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”?

Astudent showed the steps below while solving the inequality |x-4|< 1 by graphing.