3*+1 + 2.3*-1 = 99
3*-1.9 + 2.3*-1 = 99
3*-1.(9+2) = 99
3*-1.11 = 99
3*-1 = 99:11 = 9
3*-1 = 32
<=> *-1 = 2
* = 2 + 1
* = 3
Vậy * = 3
3*+1 + 2.3*-1 = 99
3*-1.9 + 2.3*-1 = 99
3*-1.(9+2) = 99
3*-1.11 = 99
3*-1 = 99:11 = 9
3*-1 = 32
<=> *-1 = 2
* = 2 + 1
* = 3
Vậy * = 3
Tìm x biết 3/1.2+3/2.3+3/3.4+....+3/99.100 + 4x=1+3+5+...+99
tbchln:
2.3^2+4.3^3
1+3+5+....+99
Tinh
1) 1^2 + 3^2 + 5^2 + ... + 97^2 + 99^2
2) 1^2 - 2^2 + 3^2 - 4^2 + ... + 99^2 - 100^2
3) 1.2^2 + 2.3^2 + 3.4^2 + ... + 98.99^2
Chứng tỏ
a, 1/2-1/4+1/8-1/16+1/32-1/64<1/3
b, 1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16
c, 1/2.3/4.5/6...9999/10000<1/100
A = 1/2.3 +1/4.5 +...+1/99. 100
Cứu mình với
Cho M=(1+1/2+1/3+...+1/98).2.3...98
CMR :M chia hết cho 99
cmr 1/2.3/4.5/6. ... .99/100 < 1/10
Cho E=1/2.3/4......99/100. CMR 3<E<6
\(\dfrac{x}{200}\)= \(\dfrac{1^2}{1.2}\) . \(\dfrac{2^2}{2.3}\) . \(\dfrac{3^2}{3.4}\) . .... .\(\dfrac{99^2}{99.100}\)