Answer:
C
Step-by-step explanation:
f(x)=72-4x
72-4x=0
4x=72
x=18
f(x)<=18
The 21st term of the given arithmetic sequence is 83. The nth term of an arithmetic sequence is applied to find the required value where n = 21.
<h3>What is the nth term of an arithmetic series?</h3>
The nth term of an arithmetic sequence is calculated by the formula
aₙ = a + (n - 1) · d
Here the first term is 'a' and the common difference is 'd'.
<h3>Calculation:</h3>
The given sequence is an arithmetic sequence.
3, 7, 11, 15, 19, ....
So, the first term in the sequence is a = 3 and the common difference between the terms of the given sequence is d = 7 - 3 = 4.
Thus, the required 21st term in the sequence is
a₂₁ = 3 + (21 - 1) × 4
⇒ a₂₁ = 3 + 20 × 4
⇒ a₂₁ = 3 + 80
∴ a₂₁ = 83
So, the 21st term in the given arithmetic sequence is 83.
Learn more about the arithmetic sequence here:
brainly.com/question/6561461
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For this case we have that by definition, the circumference of a circle is given by:

Where:
d: It is the diameter of the circle
They tell us that:

Substituting:

Thus, the circumference of the circle is 55 centimeters.
Answer:
Option B
To find AB(x) and BC(y), you can do(there are multiple ways you can do this):
tan A = 
tan 60° =
or (tan 60°) · 7 = y
tan 60° = 
√3 · 7 = y
7√3 cm = y
sin B = 
sin 30° =
or 
sin 30° =
= 
x = 
x = 14 cm
AB = 14cm
BC = 7√3 cm