Ôn tập toán 7
Các câu hỏi tương tự
\(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+...+\frac{2}{99.101}\)
\(\frac{5}{1.3}+\frac{5}{3.5}+\frac{5}{5.7}+...+\frac{2}{99.101}\)
Tính nhanh
A = \(\dfrac{2}{1.3}\) + \(\dfrac{2}{3.5}\) +\(\dfrac{2}{5.7}\) + ... + \(\dfrac{2}{97.99}\)
B = \(\dfrac{2}{1.2.3}\) + \(\dfrac{2}{2.3.4}\) + ... + \(\dfrac{2}{8.9.10}\)
1. Tìm x ϵ Q sao cho:a) (2x-3). (x+1) 0.b) left(x-frac{1}{2}right).left(x+3right) 0.2. Tính:Sfrac{1}{3.5}+frac{1}{5.7}+...+frac{1}{999.1001}3. Tìm x: Biết x không thuộc{-2; -5; -10; -17}frac{3}{left(x+2right).left(x+5right)}+frac{5}{left(x+5right).left(x+10right)}+frac{7}{left(x+10right).left(x+17right)}frac{x}{left(x+2right).left(x+17right)}
Đọc tiếp
1. Tìm x ϵ Q sao cho:
a) (2x-3). (x+1) < 0.
b) \(\left(x-\frac{1}{2}\right).\left(x+3\right)\)> 0.
2. Tính:
S=\(\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{999.1001}\)
3. Tìm x: Biết x không thuộc{-2; -5; -10; -17}
\(\frac{3}{\left(x+2\right).\left(x+5\right)}+\frac{5}{\left(x+5\right).\left(x+10\right)}+\frac{7}{\left(x+10\right).\left(x+17\right)}=\frac{x}{\left(x+2\right).\left(x+17\right)}\)
Tính :
\(\frac{5}{1.3}+\frac{5}{3.5}+\frac{5}{5.7}+...+\frac{5}{99.101}\)
TÍNH TỔNG
S= \(\left(1+\dfrac{1}{1.3}\right)\left(1+\dfrac{1}{3.5}\right)\left(1+\dfrac{1}{5.7}\right)...(1+\dfrac{1}{2007.2009})\)
tìm x nguyên biết
a) \(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{\left(2x-1\right)\left(2x+1\right)}=\frac{49}{99}\)
tính:
a. -1/21 + -1/28
b. -8/18 -15/27
c. -5/12 + 0.75
d 3.5 - (-2/7)
\(\frac{45^6.\left(\frac{1}{2}\right)+5^8}{3^3.5^6-5^6}\)
tính nhanh gọn giúp mk