সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=648$$ এবং সাধারণ অনুপাত: $$r=1.5$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=648$$

$$a_2=a_1·r^{n-1}=648\cdot {1.5}^{2-1}=648\cdot {1.5}^1=648\cdot 1.5=972$$

$$a_3=a_1·r^{n-1}=648\cdot {1.5}^{3-1}=648\cdot {1.5}^2=648\cdot 2.25=1458$$

$$a_4=a_1·r^{n-1}=648\cdot {1.5}^{4-1}=648\cdot {1.5}^3=648\cdot 3.375=2187$$

$$a_5=a_1·r^{n-1}=648\cdot {1.5}^{5-1}=648\cdot {1.5}^4=648\cdot 5.0625=3280.5$$

$$a_6=a_1·r^{n-1}=648\cdot {1.5}^{6-1}=648\cdot {1.5}^5=648\cdot 7.59375=4920.75$$

$$a_7=a_1·r^{n-1}=648\cdot {1.5}^{7-1}=648\cdot {1.5}^6=648\cdot 11.390625=7381.125$$

$$a_8=a_1·r^{n-1}=648\cdot {1.5}^{8-1}=648\cdot {1.5}^7=648\cdot 17.0859375=11071.6875$$

$$a_9=a_1·r^{n-1}=648\cdot {1.5}^{9-1}=648\cdot {1.5}^8=648\cdot 25.62890625=16607.53125$$

$$a_{10}=a_1·r^{n-1}=648\cdot {1.5}^{10-1}=648\cdot {1.5}^9=648\cdot 38.443359375=24911.296875$$