Ron has d dollars. Xavier has five dollars less than Ron. Which expression represents the amount of money that Xavier has?
A $5-d
B. d-$5
C. d + $5
D. $5 d

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?

What is the distance between point a and b

Having a hard time understanding this question (see attachment).