What is the difference 31-29 it has a tens and ones box on top of the numbers i dont understand its a 2 digit subtraction and it say regroup if you need to someone

Which function is increasing? o a. f(x)=(1/15)* o b. f(x)= (0.5)* o c. f(x)=(1/5)* o d. f(x) = 5*

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.