Answer:
6d^2 - 8d
Step-by-step explanation:
Multiply 2d to the other two monomials
The problem statement gives you the relationship between their speeds, and it gives you information you can use to find their total speed. You solve this by finding the total speed, then the proportion of that belonging to Bill.
The total speed is (120 mi)/(3 h) = 40 mi/h.
The speed ratio is ...
... Bill : Joe = 3 : 1
so the speed ratio Bill : Total is ...
... 3 : (3+1) = 3:4.
Bill's speed is (3/4)×(40 mi/h) = 30 mi/h.
Yes, it is. You may prove it using something like this: 1 is an integer. 1-1 is a difference between integers. A difference between integers returns an integer, so 0 is an integer.