On the first math exam, 16 students received an A grade. On the second math exam,
12 students received an A grade. What percentage decrease is that?

A 75% decrease

Step-by-step explanation:

You set up a ratio table.

16 is 100%

12 is with an unknown percent so classified as x, since your cross multiplying, your multiplying 16 with x and 12 with 100.

You get 16x/16 = 1200/16

The two 16 cross each other out and your left with x so x is equal to 75

Thus 75%

 A 75 decrease.

Step-by-step explanation:

The person above me is correct.

b. f(x) = –√x + 3this is the correct answer

step-by-step explanation:

total income = price of one ticket   *   number of tickets sold

  y                 =     4                                   x

so the equation is y=4x     with x≥0   because number of tickets sold can not be negative

thus the equation is a semi -line with an end point at

(0,0)

passing through :

x=1     y=4(1) = 4   so through (1,4)