Answer as fast as possible

solve the equations in parts a and b using inverse operations. check your solutions. in your final answer, include all of your work.

part a: 5 + x2 = 2x2 + 13

part b: 5 + x3 = 2x3 + 13

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”?