7=3x+2y-z
How many more equations would you need to solve x, y, and z? In which variables can the additional equations be? Give examples of equations that would help solve these variables. (Hint: Select values for x, y, and z first; then multiply them by a constant and add and subtract them to create your equations.)
If you are solving for 3 variables, can you solve a system of equations when each equation only has 2 variables? If so, how many equations would be required? In general, how many equations are required to solve a system of equations in several variables? Why?