Question 327146
Problem 1:
To solve this problem, you are going to have to write an equation using what you know.  You know that a car cost $40 per day plus $0.21 per mile.  This total cost can be written as:
C = 40 + 0.21M (where C = total cost of renting a car, M = miles driven)
You also know that your total budget is $82.  This means that your total costs have to be less than or equal to $82.  So if you set the cost equation equal to $82, you will find the maximum amount of miles you can travel:
C = 40 + 0.21M
82 = 40 + 0.21M
42 = 0.21M
200 = M
So that means the best mileage you can get for $82 is 200 miles.  So your miles can be less than or equal to 200 and you will be on budget. (I'm sorry I don't understand this last part of your question: The solution is m/m is less than ??)
Problem 2:
To solve this problem, you need to write an equality using what you know.  You know that a metal stays solid below 1853.9 degrees fahrenheit:
M < 1853.9 degrees (M = temperature of the metal)
Now the question asks for the celsius temperature, so we need to change 1853.9 degrees fahrenheit into celsius using the formula F = (9/5)c + 32:
F = (9/5)c + 32
1853.9 = (9/5)c + 32
1821.9 = (9/5)c
1012.167 = c
So 1853.9 degrees F = 1012.2 degrees C.  This means that we can put this into our inequaltiy:
M < 1853.9 degrees F
M < 1012.2 degrees C
So the temperature of the metal must be less that 1012.2 degrees celsius.