Toán Lớp 6: 9/2.4 + 25/4.6 + 49/6.8 +..+10201/100.102 giúp em với ạaaaaaaaaaaaaaaaa

Question

Toán Lớp 6:  9/2.4 + 25/4.6 + 49/6.8 +..+10201/100.102 giúp em với ạaaaaaaaaaaaaaaaa

giahan44 · Answer

9/(2.4) + 25/(4.6) + 49/(6.8) + .................... + 10201/(100.102)   = (9/(2.4) - 1) + (25/(4.6) - 1) + (49/(6.8) - 1) + ............... + (10201/(100.102) - 1) + 50   = 1/(2.4) + 1/(4.6) + 1/(6.8) + ............... + 1/(100.102) + 50   = 1/2[2/(2.4) + 2/(4.6) + 2/(6.8) + .............. + 2/(100.102)] + 50   = 1/2(1/2 - 1/4 + 1/4 - 1/6 + ............... + 1/100 - 1/102) + 50   = 1/2(1/2 - 1/102) + 50   = 1/2 . 25/51 + 50   = 25/102 + 50   = 5125/102

thanhbinh2k5 · Answer

$ frac{9}{2.4}$ + $ frac{25}{4.6}$ +$ frac{49}{6.8}$ + ...+ $ frac{10201}{100.102}$    = ( $ frac{9}{2.4}$ -1) +( $ frac{25}{4.6}$ -1) + ($ frac{49}{6.8}$ -1)+ ...+( $ frac{10201}{100.102}$ -1) + 1.50   = $ frac{1}{2.4}$ + $ frac{1}{4.6}$ +$ frac{1}{6.8}$ + ...+ $ frac{1}{100.102}$ + 50   = $ frac{1}{2}$ ( $ frac{2}{2.4}$ + $ frac{2}{4.6}$ +$ frac{2}{6.8}$ + ...+ $ frac{2}{100.102}$) + 50   = $ frac{1}{2}$ ( $ frac{1}{2}$ -$ frac{1}{4}$  + $ frac{1}{4}$ - $ frac{1}{6}$+$ frac{1}{6}$ - $ frac{1}{8}$+ ...+ $ frac{1}{100}$ -$ frac{1}{102}$ ) + 50   = $ frac{1}{2}$( $ frac{1}{2}$ - $ frac{1}{102}$) + 50   = $ frac{1}{2}$ . $ frac{25}{51}$ + 50   = $ frac{5125}{102}$   C&oacute; j thắc mắc th&igrave; hỏi mk nha ^o^