Directions: Using the digits 0 to 9, at most one time each, place a digit in each box so that there is only one solution.
Hint
How could you find the equation if you already knew the solution?
Answer
There are two answers x^2 + 6x + 9 = 0 which has the solution -3 and 9x^2 + 6x + 1 = 0 which has the solution -1/3.
Source: Daniel Luevanos
Open Middle®