Answer:
x = 0, Need the steps?
STEPS:
9x - 7 = -7 (Original Problem)
9x = 0 (Add 7 to both sides)
x = 0 (Divide both sides by 9)
Answer:
No solutions
Step-by-step explanation:
31 times any positive number cannot be a negative number.

the equation is a quadratic one, and it has a positive coefficient on the leading term, meaning, is opening upwards, so it has a "burrow" for the vertex.
the minimum or lowest point for a quadratic opening upwards is, well, the vertex point :), the "x" value is the year, the "y" or f(x) value is the population, we're asked for the year, or the x-coordinate of the vertex
well