How could you use the commutative property of addition to rewrite the expression −21 + 7? a) −21(7) b) 3(−21) + 7 c) 7 + (−21) d) 3(−7) + 21 submit

Which is an equation for the nth terms of the sequence 12,15,18,21

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”?

If 7x=9y, y/z = 7/5 , then x/z = (a) 2/7 (b) 7/9 (c) 9/5 (d) 9/7 (e) 5/9