Tinh
A = 1 - \(\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-....-\frac{3}{198.500}\)
CAC BN GIUP MK NHA MK TICK DUNG CHO
Thực hiện phép tính:
\(1-\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-\frac{3}{8.25}-...-\frac{3}{198.500}\)
\(1-\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-\frac{3}{8.25}-...-\frac{3}{198.500}\)
\(=1-\left(\frac{3}{2.10}+\frac{3}{4.15}+\frac{3}{6.20}+...+\frac{3}{198.500}\right)\)
\(=1-\frac{3}{2.5}.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{99.100}\right)\)
\(=1-\frac{3}{10}.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\right)\)
\(=1-\frac{3}{10}.\left(1-\frac{1}{100}\right)\)
\(=1-\frac{3}{10}.\frac{99}{100}\)
\(=1-\frac{297}{1000}\)
\(=\frac{703}{1000}\)
P/s : Không biết đúng hông nha, làm đại
\(1-\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-\frac{3}{8.25}-....-\frac{3}{198.500}\)
thực hiện phép tính trên.
\(A=1-\left(\frac{3}{2.10}+\frac{3}{4.15}+\frac{3}{6.20}+....+\frac{3}{198.500}\right)\)
\(=1-\frac{3}{2.5}\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{99.100}\right)\)
\(=1-\frac{3}{25}\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\right)\)
\(=1-\frac{3}{25}\left(1-\frac{1}{100}\right)\)
\(=1-\frac{3.99}{25.100}=\frac{703}{1000}\)
Tính A= \(A=1-\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-...-\frac{3}{198.500}\)
Thực hiện phép tính :
\(1-\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-\frac{3}{8.25}-...-\frac{3}{198.500}\)
A= 1 - \(\frac{3}{2.10}\)- \(\frac{3}{4.15}\)- \(\frac{3}{6.20}\)- \(\frac{3}{8.25}\)- ... - \(\frac{3}{198.500}\)
\(\frac{3}{2.10}\)+ \(\frac{3}{4.15}\)+ \(\frac{3}{6.20}\)+ \(\frac{3}{8.25}\)+ .... + \(\frac{3}{198.500}\)
\(A=\frac{3}{2.1.2.5}+\frac{3}{2.2.3.5}+\frac{3}{2.3.4.5}+\frac{3}{2.4.5.5}+...+\frac{3}{2.99.100.5}\)
\(A=\frac{3}{2.5}\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{99.100}\right)\)
Đặt biểu thức trong ngoặc đơn là B
\(B=\frac{2-1}{1.2}+\frac{3-2}{2.3}+\frac{4-3}{3.4}+\frac{5-4}{4.5}+...+\frac{100-99}{99.100}\)
\(B=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{99}-\frac{1}{100}\)
\(B=1-\frac{1}{100}=\frac{99}{100}\)
\(A=\frac{3}{2.5}.B=\frac{3.99}{2.5.100}=\frac{297}{1000}\)
\(\frac{3}{2.10}\)x \(\frac{3}{4.15}\)x \(\frac{3}{6.20}\)x \(\frac{3}{8.25}\)x.....x \(\frac{3}{198.500}\)
B1:
a) \(\frac{2.3+2.4.6+3.6.9+4.8.12}{3.5+2.6.10+3.9.15+4.12.30}\)
b)\(1-\frac{3}{2.10}-\frac{3}{4.15}-\frac{3}{6.20}-\frac{3}{8.25}-...-\frac{3}{198.500}\)
B2 Tìm x biết
a)38- I x+10 I =(-6)20:(94.410)
b)1+5+9+13+...+x=5050
B3
1.CMR 1.3.5....2013.2015+2.4.6...2014.2016 chia hết cho 9911
Giải nhanh và chi tiết nha!Thank you!!!!!!!!!!
Tính:1-3/2.10 -3/4.15-3/6.20-..-3/198.500