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Find the 11th term from the last term (t...

Find the 11th term from the last term (towards the first term) of the AP 12, 8, 4,... - 84.

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To find the 11th term from the last term towards the first term of the arithmetic progression (AP) given as 12, 8, 4, ..., -84, we can follow these steps: ### Step 1: Identify the first term (A) and the common difference (D) The first term \( A \) of the AP is 12. The common difference \( D \) can be calculated as: \[ D = 8 - 12 = -4 \] ### Step 2: Identify the last term (L) The last term given in the AP is -84. ### Step 3: Determine the number of terms (n) in the AP To find the number of terms in the AP, we can use the formula for the nth term of an AP: \[ L = A + (n - 1)D \] Substituting the known values: \[ -84 = 12 + (n - 1)(-4) \] Rearranging the equation: \[ -84 - 12 = (n - 1)(-4) \] \[ -96 = (n - 1)(-4) \] Dividing both sides by -4: \[ n - 1 = 24 \] Adding 1 to both sides gives: \[ n = 25 \] ### Step 4: Find the 11th term from the last term To find the 11th term from the last term, we can use the formula for the nth term: \[ A_n = A + (n - 1)D \] In this case, we want the 11th term from the last, which means we need to find the 15th term of the original sequence (since \( 25 - 11 + 1 = 15 \)): \[ A_{15} = A + (15 - 1)D \] Substituting the values: \[ A_{15} = 12 + (14)(-4) \] Calculating: \[ A_{15} = 12 - 56 = -44 \] ### Final Answer The 11th term from the last term towards the first term of the AP is \(-44\). ---
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