49-9=???
Những câu hỏi liên quan
(1/49 – 1/9)(1/49 -1/16)(1/49 - 1/25)……..(1/49 – 1/2401)
(1/49-1/9)(1/49-1/16).....(1/49-1/49)...(1/49-1/2401)
(1/49-1/9)(1/49-1/16).....0....(1/49-1/2401)
=0
vì khoảng cách là 7 mà 49 chia hết cho 7 nên có phân số 1/49 trong dãy
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M=(1/4*9+1/9*14+1/14*19+...1/44*49)*1-3-5-7-9-...-49/89=-9/28
4×7/9×23
2×21/14×15
2×5×13/26×35
9×6-9×3/18
17×5-17/3-20
49+7×49/49
(1/4*9+1/9*14+...+1/44*49)*(1-3-5-7-...-49/89)
Câu 2:
a,-2/49-(5/3-2/49) b,C=5*4^15*9^9-4*3^20*8^9/5*2^9*6^19-7*2^29*27^6
a: =-2/49-5/3+2/49=-5/3
b: \(=\dfrac{5\cdot4^{15}\cdot9^9-4\cdot3^{20}\cdot8^9}{5\cdot2^9\cdot6^{19}-7\cdot2^{29}\cdot27^6}\)
\(=\dfrac{5\cdot2^{30}\cdot3^{18}-3^{20}\cdot2^{27}\cdot2^2}{5\cdot2^9\cdot2^{19}\cdot3^{19}-7\cdot2^{29}\cdot3^{18}}\)
\(=\dfrac{5\cdot2^{30}\cdot3^{18}-3^{20}\cdot2^{29}}{5\cdot2^{28}\cdot3^{19}-7\cdot2^{29}\cdot3^{18}}\)
\(=\dfrac{2^{29}\cdot3^{18}\left(2\cdot3-3^2\right)}{2^{28}\cdot3^{18}\left(5\cdot3-7\cdot2\right)}=2\cdot\dfrac{6-9}{15-14}=2\cdot\left(-3\right)=-6\)
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Câu 2:
a,-2/49-(5/3-2/49) b,C=5*4^15*9^9-4*3^20*8^9/5*2^9*6^19-7*2^29*27^6
( 1 / 4 . 9 + 1 / 9 . 14 + 1 / 14 . 19 + ... + 1 / 44 .49 ) . (1 - 3 - 5 - 7 - ... - 49) / 89 = ?
7*8+33-9-49+19-9+78/33=?
Từ:
7*8=?
56+33=?
89-9=?
80-49=?
49+19=?
68-9=?
79+78=?
157/33
A=(1/4*9 + 1/9*14 + 1/14*19 + ...+ 1/44*49)*1-3-5-7-..-49/89
tính 1/4*9+1/9*14+1/14*19+...+1/44*49 * 1-3-5-...-49/89 -19/28
