Ta có: 1/4 < (1+1)/(4+1) = 2/5
3/6 < (3+1)/(6+1) = 4/7
.......................
995/998 < (995+1)/(998+1) = 996/999
997/1000 <(997+1)/(1000+1) =998/1001
cho A=1\4.3\6.5\8....995\998.997\1000
B=2\5.4\7.6\9....996\999.998\1001
So sánh A và B
So sánh A và B: Cho A=1/4.3/6.5/8...995.998.997/1000
B=2/5.4/7.6/9...996/999.998/1001
Cho A=1/4.3/6...997/1000
B=2/5.4/7...998/1001
So sanh A va B
cho A= 1/4. 3/6.5/8......43/46.45/48
B= 2/5.4/7.5/9....44/47.46/49
a) so sánh A và B
b) chứng minh A< 1/133
1.
a, (7.610.220.36-219.615) : (9.619.29-4.317.226)
b, (5.415.99-4.320.89) : (5.29.619-2.229.276)
2.Cho bieu thuc
A=2010+20102+20103+.....+20102009+20102010
Chung minh rang A chia het cho 11
tính
a) A = \(\dfrac{6^3+3.6^2+3^3}{-13}\)
b) B =\(\dfrac{2.8^4.27^2+4.6^9}{2^3.6^7+2^7.40.9^4}\)
c) C=\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{16}.6^{19}-7.2^{29}.27^6}\)
\(B=\frac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^{10}.6^{19}-7.2^{29}.27^6}\)
\(\dfrac{5.4^{15}.9^9-4.3^{20}.8^9}{5.2^2.6^{19}-7.2^{29}.27^6}\)
cho :
a = 999^9 +999^8
b = 1000^9
so sánh a và b