Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Bài 1: Tính
1/ \(\dfrac{-2}{-5}-\left(\dfrac{-4}{3}\right)\)
\(=\dfrac{2}{5}-\left(\dfrac{-4}{3}\right)\)
\(=\dfrac{6}{15}-\left(\dfrac{-20}{15}\right)\)
\(=\dfrac{6-\left(-20\right)}{15}\)
\(=\dfrac{26}{15}\)
2/ \(\left(\dfrac{-2}{4}-\dfrac{1}{2}\right):\dfrac{2}{3}\)
\(=\left(\dfrac{-2}{4}-\dfrac{2}{4}\right):\dfrac{2}{3}\)
\(=-1:\dfrac{2}{3}\)
\(=-1.\dfrac{3}{2}\)
\(=\dfrac{-3}{2}\)
3/ \(\dfrac{5}{12}.\dfrac{17}{11}-\dfrac{5}{12}.\dfrac{7}{11}+\dfrac{5}{12}.\dfrac{1}{11}\)
\(=\dfrac{5}{12}.\left(\dfrac{17}{11}-\dfrac{7}{11}+\dfrac{1}{11}\right)\)
\(=\dfrac{5}{12}.\left(\dfrac{17-7+1}{11}\right)\)
\(=\dfrac{5}{12}.1\)
\(=\dfrac{5}{12}\)
3/7 *14/5 - 1/2 = 6/5-1/2 = 7/10
2/5 - 3/5 *5/10 = 2/5 - 3/10 = 1/10
4/13 *5/11 + 4/13 *6/11 - 4/13
= 4/13*5/11 +4/13 *6/11 - 4/13 *1
= 4/13 *(5/11+ 6/11 - 1)
= 4/13 *0
=0
\(\left(\dfrac{2}{3}-\dfrac{5}{11}+\dfrac{1}{4}\right):\left(1+\dfrac{5}{12}-\dfrac{7}{11}\right)\)
\(=\left(\dfrac{22}{33}-\dfrac{15}{33}+\dfrac{1}{4}\right):\left(1+\dfrac{5}{12}-\dfrac{7}{11}\right)\)
\(=\left(\dfrac{7}{33}+\dfrac{1}{4}\right):\left(\dfrac{12}{12}+\dfrac{5}{12}-\dfrac{7}{11}\right)\)
\(=\left(\dfrac{28}{132}+\dfrac{33}{132}\right):\left(\dfrac{17}{12}-\dfrac{7}{11}\right)=\dfrac{61}{132}:\dfrac{103}{132}\)
\(=\dfrac{61}{132}\times\dfrac{132}{103}=\dfrac{8052}{13596}=\dfrac{61}{103}\)