Answer:
x
Step-by-step explanation:
Scientists like to say that the “independent” variable goes on the x-axis (the bottom, horizontal one) and the “dependent” variable goes on the y-axis (the left side, vertical one).
Answer:
Option B: 
Step-by-step explanation:
The parabola has its concavity downwards, so we need a function in the model:

With a negative value of 'a'
The vertex is (0,0), so we have that:


The x-coordinate of the vertex is given by the equation:



So we have a function in the model:

With a < 0
The only option with this format is B:

Answer:
x = 21
Step-by-step explanation:
Givens:
Every triangle's interior angles add up to 180°
The triangle has a right angle.
The triangle is isosceles (two equal sides and two equal angles)
Let's make an equation with the information we have already.
2 × (2x + 3) + 90 = 180
4x + 6 + 90 = 180
4x + 96 = 180
4x = 84
x = 21