if the number (3x+2)(2x+3) and (2x-5) are in AP then the value of x
Answers
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✝️ Required Answer:
✏ GiveN:
- (3x +2), (2x + 3) and (2x -5) are in AP
✏ To finD:
- Find the value of x ......?
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✝️ How to solve?
In an AP, the consecutive terms have an common difference. It is a successive additive series in which common difference is always same for consecutive terms.
- Let a, b and c are in AP
❇ Then, b - a = c - b
➙ b + b = a + c
➙ 2b = a + c
So, here we can say that, twice the second term = sum of first and third term in the series. Or the second term is the average of the first and third term.
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✝️ Solution:
Let,
- a = 3x + 2
- b = 2x + 3
- c = 2x - 5
Then, On the basis of above relation,
➙ 2(2x + 3) = 3x + 2 + 2x - 5
➙ 4x + 6 = 5x - 3
➙ 5x - 4x = 6 + 3
➙ x = 9
Verification:
If x = 9, then
- a = 3(9) + 2 = 29
- b = 2(9) + 3 = 21
- c = 2(9) - 5 = 13
Here, b - a = c - b = - 8, common difference.
So, a, b and c are in AP. (Verified!)
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Here,
1st term is ( 3x + 2 )
2nd term is ( 2x + 3 )
3rd term is ( 2x - 5 )
Common difference ( d ) = >
( 2x + 3 ) - ( 3x + 2 ) = ( 2x - 5 ) - ( 2x + 3 )
= = > 2x + 3 - 3x - 2 = 2x - 5 - 2x - 3
= = > 2x - 3x + 3 - 2 = 2x - 2x - 5 - 3
= = > 1 - x = - 8
= = > x = 9
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VERIFICATION :-
( 3x + 2 ) = > 3(9) + 2 => 27 + 2 = 29
( 2x + 3 ) = > 2(9) + 3 => 18 + 3 => 21
( 2x - 5 ) = > 2(9) - 5 => 18 - 5 = 13
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21 - 29 = 13 - 21 = - 8
These are in AP ..........