Step-by-step explanation:
the formula to calculate a circumference is

(consider x as the diameter)
so I'll be noting the circumference as C alongside the circle's ranking
a.

b.

c.

hope I helped
N = nickels and q = quarters
0.05n + 0.25q = 1.90
n = 2q + 3
0.05(2q + 3) + 0.25q = 1.90
0.10q + 0.15 + 0.25q = 1.90
0.10q + 0.25q = 1.90 - 0.15
0.35q = 1.75
q = 1.75/0.35
q = 5 ......there are 5 quarters
n = 2q + 3
n = 2(5) + 3
n = 10 + 3
n = 13 <=== there are 13 nickels
The slope would be 0
This is basically how you do it if you need more help let me know
I do not the question. Please explain
Use the website Symbolab. It's helped with all of my calculus problems.