The graph shows the number of paintballs a machine launches, y, in x seconds:

a graph titled rate of launch is shown. the x axis label is time in seconds, and the x axis values are from 0 to 20 in increments of 4 for each grid line. the y axis label is number of balls, and the y axis values from 0 to 100 in increments of 20 for each grid line. a line is shown connecting points on ordered pair 4, 20 and 8, 40 and 12, 60 and 16, 80.

which expression can be used to calculate the rate per second at which the machine launches the balls?

fraction 80 over 4
fraction 20 over 4
fraction 4 over 80
fraction 4 over 20

Per the chart the rates are 20 balls in 4 seconds ( 20 over 4), 40 balls in 8 seconds ( 40 over 8), 60 balls in 12 seconds ( 60 over 12)  and 80 balls in 16 seconds ( 80 over 16).

The answer B. 20 over 4

let's add {f(x)=x+1}f(x)=x+1 and {g(x)=2x}g(x)=2x together to make a new function.

f(x)+g(x) =(x+1)+(2x)=x+1+2x=3x+1

let's call this new function hh. so we have:

{h(x)}={f(x)}+{g(x)}{=3x+1}h(x)=f(x)+g(x)=3x+1

we can also evaluate combined functions for particular inputs. let's evaluate function hh above for x=2x=2. below are two ways of doing this.

method 1: substitute x=2x=2 into the combined function hh.

h(x)

h(2)

​    

=3x+1

=3(2)+1

=7

​ since h(x)=f(x)+g(x)h(x)=f(x)+g(x), we can also find h(2)h(2) by finding f(2) +g(2)f(2)+g(2).

first, let's find f(2)f(2):

f(x)

f(2)

​    

=x+1

=2+1

=3

​  

now, let's find g(2)g(2):

g(x)

g(2)

​    

=2x

=2⋅2

=4

​  

so f(2)+g(2)=3+4=\greend7f(2)+g(2)=3+4=7.

notice that substituting x =2x=2 directly into function hh and finding f(2) + g(2)f(2)+g(2) gave us the same answer!

sinn is the total amount of students now and m were the students before, you subtract them both (n-m) and divide that by m. then, since to get a percentage from a fraction you have to multiply by 100, your answer should look like this: n-m/m*100

step-by-step explanation: