Assume the parabola is placed on a graph where the x-axis is the top of the dish.
The vertex is then at (0,-30) The x-intercepts or zeros are at (-30,0) and (30,0)
The equation of such parabola would be:

Plug in vertex to find value of 'a'

Now find the focus given that


Answer: the microphone should be placed 7.5 inches from vertex.
Answer:
what do you need help with
Step-by-step explanation:
Answer: 9 subtracted from y and multiplied by 2
Answer: 19 coins
Step-by-step explanation:
38-19=19
To check, take any one of the nubers and replace it with x, and when you solve for x. you'll get that number back. For example:
Let x represent the amount used to buy a notebook
19+x=38
x=38-19
x=19