here is the answer its in the picture and it also has the solution in picture 2
Answer:

Step-by-step explanation:
Set up an equation and solve for r using the formula for slope:

In order to find what fraction describes this percentage, you first need to know that no matter what percentage you are working with, if you want to convert it into a fraction, put the 35 as the numerator and 100 as the denominator. If you still don't know what I mean, 35 at the top of the fraction and 100 at the bottom. Like this; 35/100. Then, you can simplify it by finding a common multiple between 35 and 100. For example, 5 can be divided into 35 and 100. 35 divided by 5 is 7 and 100 divided by 5 is 20. Your result is 7/20, which can further no more be simplified because there are no more common multiples between the two numbers.
F=5 dollar bills
t=twent dollar bills
38 total bills
f+t=38
400 in bills
400=5f+20t
we have
f+t=38
5f+20t=400
multipy first equation by -5 and add to second equation
-5f-5t=-190
5f+20t=400 +
0f+15t=210
15t=210
divide both sides by 15
t=14
subsitute
t+f=38
15+f=38
f=23
23 five dolar bills
15 twenty dollar bills