Tính giá trị của các biểu thức : A= -5,13 :( \(\frac{145}{28}-\frac{17}{9}.1,25+\frac{79}{63}\))
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 1:
a) Ta có:
\(3,2\cdot x+\left(-1,2\right)\cdot x+2,7=-4,9\)
\(\Rightarrow\left[3,2+\left(-1,2\right)\right]\cdot x=\left(-4,9\right)-2,7\)
\(\Rightarrow2x=-7,6\)
\(\Rightarrow x=\left(-7,6\right):2\)
\(\Rightarrow x=-3,8\)
Vậy \(x=-3,8\)
b) Ta có:
-5,6.x+2,9.x-3,86=-9,8
=>[(-5,6)+2,9].x=(-9,8)+3,86
=>(-2,7).x=-5,94
=>x=(-5,94):(-2,7)
=>x=2,3
Vậy x=2,2
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=-5,13:\left(5\dfrac{5}{28}-1\dfrac{8}{9}.1,25+1\dfrac{16}{63}\right)\)
\(=-5,13:\left(5\dfrac{5}{28}-2\dfrac{13}{36}+1\dfrac{16}{63}\right)\)
\(=5,13:\left[\left(5-2+1\right)+\left(\dfrac{5}{28}-\dfrac{13}{36}+\dfrac{16}{63}\right)\right]\)
\(=5,13:\left(4+\dfrac{1}{14}\right)\)
\(=1,26\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) \(-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
\(=-5,13:\left(\frac{145}{28}-\frac{17}{9}.1,25+\frac{79}{63}\right)\)
\(=-5,13:\left(\frac{145}{28}-\frac{85}{36}+\frac{79}{63}\right)\)
\(=-5,13:\frac{57}{14}\)
\(=-\frac{63}{50}\)
b) \(\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}.\left(\frac{62}{75}-\frac{4}{25}\right)\right)\)
\(=\left(\frac{10}{3}.1,9+19,5:\frac{13}{3}\right).\left(\frac{62}{75}-\frac{4}{25}\right)\)
\(=\left(\frac{19}{3}+\frac{9}{2}\right).\frac{2}{3}\)
\(=\frac{65}{6}.\frac{2}{3}\)
\(=\frac{65}{9}\)
^...^
^_^
![](https://rs.olm.vn/images/avt/0.png?1311)
\(A=-5,13:\left(5\frac{5}{28}-1\frac{8}{9}.1,25+1\frac{16}{63}\right)\)
\(A=-5,13:\left(5\frac{5}{28}-\frac{85}{36}+1\frac{16}{63}\right)\)
\(A=-5,13:\frac{57}{14}=-\frac{63}{50}\)
\(B=\left(3\frac{1}{3}.1,9+19,5:4\frac{1}{3}\right).\left(\frac{62}{72}-\frac{4}{25}\right)\)
\(B=\left(\frac{19}{3}+\frac{9}{2}\right).\frac{631}{900}\)
\(B=\frac{65}{6}.\frac{631}{900}=\frac{8203}{1080}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
A = \(-\frac{513}{100}:\left(\frac{145}{4.7}-\frac{17}{9}.\frac{5}{4}+\frac{79}{7.9}\right)=-\frac{513}{100}:\frac{145.9-17.5.7+79.4}{4.7.9}=-\frac{513}{100}:\frac{57}{14}\)
A = \(-\frac{513}{100}.\frac{14}{57}=\frac{-63}{50}\)