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The sum of three consecutive terms is 15 and their product is 45 |
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Answer» Step-by-step explanation: the AP can be written as (a-d), a ,(a+d). we can write like this because the terms still have a difference of d. their SUM is 15, therefore (a-d)+a+(a+d) = 15 3a = 15 a = 5. now their product is 45. therefore (5-d)(5)(5+d) = 45 (5) [(5-d)(5+d)] = 45 5 × [25-d²]= 45 25-d² = 9 d²= 25-9 d = +or- 4 therefore the ap when d is +4 is (5-4),(5),(5+4). i.e 1, 5, 9 the ap when d = -4 is [5-(-4)] , 5, [5+(-4)] i.e 9, 5, 1. |
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