Represent the following sentence as an algebraic expression, where "a number" is the letter x. \text{3 less than a number.} 3 less than a number. plss asap

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items

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”?

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me