Answer:
33beacuse you i have -90×+60=9×6=369-63
Step-by-step explanation:
crossmultiply and divide both sides by the co efficient of x
I would say C.
A and B make no sense, you want to divide the group randomly because you want to test the new medicine. D is a bit more logical than A and B but still can't, because that isn't random.
Answer:
4.5 hours
Step-by-step explanation:
So, let's write a function p(x) which represents the total cost.
Let's let x represent the amount of hours.
The cost of a piece is a constant 10.
And there is a $8 fee per hour. In other words:

We spent a total of $46.
So, substitute in 46 for p(x) and solve for x:

Subtract 10 from both sides:

Divide both sides by 8:

Reduce:

So, we spent about 4.5 hours.