You don't have the graph icon here, so we'll have to graph this parabola without it.
Your parabola is y = -x^2 + 3., which resembles y = a(x-h)^2 + k. We can tell immediately that this parabola opens down and that the vertex is (0,3).
Plot (0,3). Besides being the vertex, this point is also the max. of the function.
Now calculate four more points. Choose four arbitrary x-values, such as {-2, 1, 4, 5} and find the y value for each one. Plot the resulting four points. Draw a smooth curve thru them, remembering (again) that the vertex is at (0,3) and that the parabola opens down.
Answer:
Given the expression:
1.

we know:

then;

Therefore, the value of expression
is -16 i.e negative.
2.

we know:


then;

Therefore, the expression
is 16 i.e Positive.
3.

we know:

then;

Therefore, the expression
is 16 i.e Positive.
I don't understand what you're asking, is there supposed to be a picture with the question?
Answer:
About 5,000 kilograms
Step-by-step explanation:
Look on the x-axis for 18 years. Then go up to where the plotted line is on 18 years to find the y-axis or the mass.