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
2x+8=20
2x=20-8
2x=12
12/2=x
6=x
Answer:
Step-by-step explanation:
To prove: The sum of a rational number and an irrational number is an irrational number.
Proof: Assume that a + b = x and that x is rational.
Then b = x – a = x + (–a).
Now, x + (–a) is rational because addition of two rational numbers is rational (Additivity property).
However, it was stated that b is an irrational number. This is a contradiction.
Therefore, the assumption that x is rational in the equation a + b = x must be incorrect, and x should be an irrational number.
Hence, the sum of a rational number and an irrational number is irrational.
450/30
15
15/3x =5
x= 5
5+2y= 315
5-5+2y =315-5
2y = 310
2y/2 = 310/2
y=155
Step-by-step explanation:
450/45
10
2x+4y=450
2×5=10
10+(4×155)
=620/155
=4
10/5=2