The sum of three terms in an AP is 33 and their product is 155. Find the terms
Answers
Correct Question:
The sum of three terms in an AP is 33 and their product is 1155. Find the terms.
Answer:
In an AP:
When a = 11 and d = + 4
- Terms: 7, 11, 15
When a = 11 and d = - 4
- Terms: 15, 11, 7
Step-by-step explanation:
Given that:
- The sum of three terms in an AP is 33.
- Their product is 1155.
To Find:
- What are these terms?
Let us assume:
- First term = (a - d)
- Second term = a
- Third term = (a + d)
According to the question.
Sum of three terms = 33
⟶ (a - d) + a + (a + d) = 33
⟶ a - d + a + a + d = 33
Cancelling d.
⟶ 3a = 33
⟶ a = 33/3
⟶ a = 11
Products of these terms = 1155
⟶ (a - d) × a × (a + d) = 1155
Substituting the value of a.
⟶ (11 - d) × 11 × (11 + d) = 1155
⟶ (11 - d) × (11 + d) = 1155/11
⟶ (11 - d) × (11 + d) = 105
Applying algebraic identities.
⟶ 11² - d² = 105
⟶ 121 - d² = 105
⟶ d² = 121 - 105
⟶ d² = 16
⟶ d = √16
⟶ d = ± 4
We have:
- The value of a = 11
- The value of d = ± 4
When d = + 4
- First term = (a - d) = (11 - 4) = 7
- Second term = a = 11
- Third term = (a + d) = (11 + 4) = 15
When d = - 4
- First term = (a - d) = 11 - (- 4) = 11 + 4 = 15
- Second term = a = 11
- Third term = (a + d) = 11 + (- 4) = 11 - 4 = 7
refer attachment
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