Đơn giản biểu thức sau:
A= 12\13+12\131-12\1313+12\13131
15\13+15\131-15\1313+15\13131
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
A =\(\frac{\frac{12}{13}+\frac{12}{131}-\frac{12}{1313}+\frac{12}{13131}}{\frac{15}{13}+\frac{15}{131}-\frac{15}{1313}+\frac{15}{13131}}=\frac{12.\left(\frac{1}{13}+\frac{1}{131}-\frac{1}{1313}+\frac{1}{13131}\right)}{15.\left(\frac{1}{13}+\frac{1}{131}-\frac{1}{1313}+\frac{1}{13131}\right)}=\frac{12}{15}=\frac{4}{5}\)
Tick ủng hộ nha mọi người
\(\dfrac{\left(12:13\right)+\left(12:131\right)-\left(12:1313\right)+\left(12:13131\right)}{\left(15:13\right)+\left(15:131\right)-\left(15:1313\right)+\left(15:13131\right)}\\ =\dfrac{12:\left(13+131-1313+13131\right)}{15:\left(13+131-1313+13131\right)}=\dfrac{12}{15}=\dfrac{4}{5}\)
=>B=\(\frac{12.\left(\frac{1}{13}+\frac{1}{1313}+\frac{1}{131}+\frac{1}{1313}\right)}{15.\left(\frac{1}{13}+\frac{1}{1313}+\frac{1}{131}+\frac{1}{1313}\right)}\)
=>B=\(\frac{12}{15}\)
=>B=\(\frac{4}{5}\)
B = \(\frac{12.\left(\frac{1}{13}+\frac{1}{1313}+\frac{1}{131}-\frac{1}{1313}\right)}{15.\left(\frac{1}{13}+\frac{1}{131}-\frac{1}{1313}+\frac{1}{1313}\right)}\)
=\(\frac{12.\left(\frac{1}{13}+\frac{1}{131}\right)}{15.\left(\frac{1}{13}+\frac{1}{131}\right)}\)
=\(\frac{12}{15}=\frac{4}{5}\)
Vậy B = 4/5.
Ta có 1212/1313= 12/13
=> 1212/1313 =12/13
\(\dfrac{5}{7}\)>\(\dfrac{6}{21}\)
\(\dfrac{18}{24}\)>\(\dfrac{15}{25}\)
\(\dfrac{12}{13}\)=\(\dfrac{1212}{1313}\)
a) \(\dfrac{12}{14}=\dfrac{1200}{1400}=\dfrac{1400-200}{1400}=1-\dfrac{200}{1400}\)
\(\dfrac{1212}{1414}=\dfrac{1414-200}{1414}=1-\dfrac{200}{1414}\)
vì \(\dfrac{200}{1414}< \dfrac{200}{1400}\)
Nên \(1-\dfrac{200}{1400}< 1-\dfrac{200}{1414}\)
Vậy \(\dfrac{12}{14}< \dfrac{1212}{1414}\)
Các bài sau tương tự
a/\(\frac{1212}{1313}=\frac{12x101}{13x101}=\frac{12}{13}\)
Vậy \(\frac{12}{13}=\frac{1212}{1313}\)
b/Ta có:
\(\frac{4}{5}< 1\)
\(\frac{10}{9}>1\)
=>\(\frac{4}{5}< 1< \frac{10}{9}\Rightarrow\frac{4}{5}< \frac{10}{9}\)
c/\(\frac{17}{15}=1+\frac{2}{15}\)
\(\frac{31}{29}=1+\frac{2}{29}\)
Vì \(\frac{2}{15}>\frac{2}{29}\) nên \(\frac{17}{15}>\frac{31}{29}\)
-------------
chú ý: dấu "=>" có nghĩa là "suy ra"