The sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Given,
18th term of an arithmetic sequence = 8.1
Common difference = d = 0.25.
<h3>What is an arithmetic sequence?</h3>
The sequence in which the difference between the consecutive term is constant.
The nth term is denoted by:
a_n = a + ( n - 1 ) d
The sum of an arithmetic sequence:
S_n = n/2 [ 2a + ( n - 1 ) d ]
Find the 18th term of the sequence.
18th term = 8.1
d = 0.25
8.1 = a + ( 18 - 1 ) 0.25
8.1 = a + 17 x 0.25
8.1 = a + 4.25
a = 8.1 - 4.25
a = 3.85
Find the sum of 20 terms.
S_20 = 20 / 2 [ 2 x 3.85 + ( 20 - 1 ) 0.25 ]
= 10 [ 7.7 + 19 x 0.25 ]
= 10 [ 7.7 + 4.75 ]
= 10 x 12.45
= 124.5
Thus the sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
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Answer:
b
Step-by-step explanation:
b
Answer:
1. congruent
2. congruent
3. not congruent
4. not congruent
5. congruent
6. congruent
7. congruent
8. congruent
9. congruent
Step-by-step explanation:
Answer:
The solution of system of equation is (-2,0)
Step-by-step explanation:
Given system of equation are
Equation 1 : 2x+y=(-4)
Equation 2 : y+
x=(-1)
To plot the equation of line, we need at least two points
For Equation 1 : 2x+y=(-4)
Let x=0
2x+y=(-4)
2(0)+y=(-4)
y=(-4)
Let x=1
2x+y=(-4)
2(1)+y=(-4)
y=(-6)
Therefore,
The required points for equation is (0,-4) and (1,-6)
For Equation 2 : y+
x=(-1)
Let x=0
y+
x=(-1)
y+
(0)=(-1)
y=(-1)
Let x=2
y+
x=(-1)
y+
(2)=(-1)
y=(-2)
The required points for equation is (0,-1) and (2,-2)
Now, plot the graph using this points
From the graph,
The red line is equation 1 and blue line is equation 2
Since. The point of intersection is solution of system of equations
The solution of system of equation is (-2,0)
Answer:
9.) The Outlier is 18
-The outlier is the number that stands out and is different