Do number 11 in your own way.

- A common unit of measurement for water's density is gram per milliliter (1 g/ml) or 1 gram per cubic centimeter (1 g/cm3). Actually, the exact density of water is not really 1 g/ml, but rather a bit less (very, very little less), at 0.9998395 g/ml at 4.0° Celsius (39.2° Fahrenheit).
- Water density changes with temperature and salinity. Density is measured as mass (g) per unit of volume (cm³). Water is densest at 3.98°C and is least dense at 0°C (freezing point). Water density changes with temperature and salinity.
- When water is a liquid, the water molecules are packed relatively close together but can slide past each other and move around freely (as stated earlier, that makes it a liquid). Pure water has a density of 1.000 g/cm3 at 4˚ C. As the temperature increases or decreases from 4˚ C, the density of water decreases.
Step-by-step explanation:

From what I got there is one real solution :)
Rearrange the second equation to give y=2-2x, substitute into the first equation to give you a value for x and then using that you can work out y for the exact coordinates of intersection :)
Also they are both straight line graphs so they will either have one or no solutions
Hope this helped :)
4 pounds of books because 60 oz only equals 3.75 pounds.