First person to ANSWER me the number of weeks in a year will get brainliest… its for my social stuidies

This is different from the first one can someone me

The suare root of 9x plus 7 plus the square rot of 2x equall to 7

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”?