To find this, first find the factor or rate of which the numbers are moving. To do so do as follows.
subtract 1 from 3
3-1=2
So each number is having 2 added to it.
Now add two to 7 and the numbers afterwards till you get the 12th term
7+2=9
1+3+5+7+9
9+2=11
1+3+5+7+9+11
11+2=13
1+3+5+7+9+11+13
13+2=15
1+3+5+7+9+11+13+15
15+2=17
1+3+5+7+9+11+13+15+17
17+2=19
1+3+5+7+9+11+13+15+17+19
19+2=21
1+3+5+7+9+11+13+15+17+19+21
21+2=23
1+3+5+7+9+11+13+15+17+19+21+23
So 23 is the 12th term
6d -11/2 = 2d -13/2
Subtract 2d from both sides
6d -11/2 - 2d = 2d -13/2 - 2d
Simplifying
4d -11/2 = -13/2
Add 11/2 to both sides
4d -11/2 + 11/2 = -13/2 + 11/2
Simplifying
4d = -2/2
4d = -1
Divide both sides by 4
4d/4 = -1/4
Simplifying
d = - 1/4
Answer: Choice A) 8.742 * 10^7
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Work Shown:
Extra info:
which is a little over 87.4 million
Draw
Left side:
(1)Square=1 (1)Triangle=5 (1)Circle=6
1+5=6+6=12
Right side: (2)Circle=6
6+6=12
