Answer:
Step-by-step explanation:
The formula for determining the sum of the first n terms of an arithmetic sequence is expressed as
Sn = n/2[2a + (n - 1)d]
Where
n represents the number of terms in the arithmetic sequence.
d represents the common difference of the terms in the arithmetic sequence.
a represents the first term of the arithmetic sequence.
If a = 5, the expression for the sum of the first 12 terms is
S12 = 12/2[2 × 5 + (12 - 1)d]
S12 = 6[10 + 11d]
S12 = 60 + 66d
Also, the expression for the sum of the first 3 terms is
S3 = 3/2[2 × 5 + (3 - 1)d]
S3 = 1.5[10 + 2d]
S3 = 15 + 3d
The sum of the first 12 terms is equal to ten times the sum of the first 3 terms. Therefore,
60 + 66d = 10(15 + 3d)
60 + 66d = 150 + 30d
66d + 30d = 150 - 60
36d = 90
d = 90/36
d = 2.5
For S20,
S20 = 20/2[2 × 5 + (20 - 1)2.5]
S20 = 10[10 + 47.5)
S20 = 10 × 57.5 = 575
Answer:
Step-by-step explanation:
Because the coordinates for x = 0 is (0,-2) so that's your y- intercept.
Then if you all you have to do is make sure that you have the correct slope.
So i just made a table on paper and started going up and seeing what slope i'd need to match the table on the screen.
Answer:42
Step-by-step explanation:
the " l l " on the -14 cancel out the negative
I pretty sure you times it by 3 and then you get 21:18
Y-intercept happens when the x-coordinate equals zero
Subtitute x with 0 from the equation
<span>3x - 2y = 6
3(0) - 2y = 6
0 - 2y = 6
-2y = 6
y = 6/-2
y = -3
The y-intercept is -3</span>
