Carmen rents roller skates for $5 plus $2 for every hour she uses them. Define the variable and write an expression for the total cost to rent roller skates. Then find the total cost if Carmen rest them for 4 hours.

Given:

Carmen rents roller skates for $5 plus $2 for every hour she uses them.

To find:

The expression for the total cost to rent roller skates. Then find the total cost if Carmen rest them for 4 hours.

Solution:

We have,

Fixed rent = $5

Additional rent = $2 per hour.

Let x be the number of hours.

So, additional rent is $2x.

Now,

Total rent = Fixed rend + Additional rent

                = $(5+2x)

So, the expression for total cost is $(5+2x).

Carmen rent them for 4 hours. So, x=4 and the total cost is

Therefore, the total cost of 4 hours is $13.

1gm = 1000mg so 0.1gm = 1000mg

first, convert the weight to kg

160lb * 1kg/2.2lb = 72.7kg

next, the dose

72.7kg * 100mg/kg = 7270mg