Answer:
Your answer is dilation.
Step-by-step explanation:
A dilation either shrinks or makes the shape bigger. It changes the size.
To do the first question, simplify the equation, putting like terms together, by adding and subtracting to do this.
Then looking at the equation that you solved for, look and see if there are any other equations that are related in some way to the original solved equation.
Pay close attention to the positive and negative signs.
30 plus EF = 180
Ef = 150
circumscribed angle plus the central angle is 180
The answer is 30.25 or as a fraction 30 1/4

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