45:\(2\dfrac{4}{7}+50\%-1,25\)
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
29 tháng 4 2023
`= -45 \div 18/7-0,5+1,25`
`= -17,5-0,5+1,25`
`= -18+1,25=-16,75`
31 tháng 7 2021
a) 6,5% của 320m là 20,8 m
b) \(\dfrac{2}{7}\)của 21km là 6 km
c) 1,25 của 84 tấn là 105 tấn
d) \(1\dfrac{3}{4}\) của 1,25 giờ là 2,1875 giờ
e) \(1\dfrac{1}{4}\) của 2 giờ là 2,5 giờ
g) \(\dfrac{2}{11}\) của 22% là 4%
LH
2
25 tháng 7 2021
\(\left|-1,25:\dfrac{7}{4}\right|+\left|-\dfrac{2}{7}\right|=\left|-\dfrac{5}{4}.\dfrac{4}{7}\right|+\dfrac{2}{7}\)
\(=\dfrac{5}{7}+\dfrac{2}{7}=1\)
25 tháng 7 2021
\(\left|-1.25:\dfrac{7}{4}\right|+\left|\dfrac{-2}{7}\right|\)
\(=\left|\dfrac{-5}{4}\cdot\dfrac{4}{7}\right|+\left|\dfrac{-2}{7}\right|\)
\(=\dfrac{5}{7}+\dfrac{2}{7}=1\)
TH
1
H
14 tháng 4 2018
Giải:
a) \(25\%-\dfrac{5}{4}+\dfrac{11}{6}\)
\(=\dfrac{1}{4}-\dfrac{5}{4}+\dfrac{11}{6}\)
\(=-1+\dfrac{11}{6}\)
\(=\dfrac{5}{6}\)
Vậy ...
b) \(75\%:\dfrac{11}{5}-\left(0,5\right)^2.\left(-7\right)+2,5\left(\dfrac{23}{3}-\dfrac{17}{3}\right)\)
\(=\dfrac{3}{4}:\dfrac{11}{5}-\dfrac{1}{4}.\left(-7\right)+2,5.2\)
\(=\dfrac{15}{44} +\dfrac{7}{4}+5\)
\(=\dfrac{23}{11}+5\)
\(=\dfrac{78}{11}\)
Vậy ...
c) \(45:\dfrac{18}{7}+50\%-1,25\)
\(=45:\dfrac{18}{7}+\dfrac{1}{2}-\dfrac{5}{4}\)
\(=\dfrac{35}{2}+\dfrac{1}{2}-\dfrac{5}{4}\)
\(=18-\dfrac{5}{4}\)
\(=\dfrac{67}{4}\)
Vậy ...
VD
23 tháng 3 2022
\(a,\dfrac{1}{6}+\dfrac{7}{3}-\dfrac{1}{2}\\ =\dfrac{1}{6}+\dfrac{14}{6}-\dfrac{3}{6}\\ =\dfrac{12}{6}\\ =2\\ b,\left(-1\dfrac{5}{8}\right)+1,25:\left(1-\dfrac{9}{4}\right)\\ =\dfrac{-13}{8}+\dfrac{5}{4}:\dfrac{5}{4}\\ =\dfrac{-13}{8}+1\\ =\dfrac{-13}{8}+\dfrac{8}{8}\\ =\dfrac{5}{8}\)
23 tháng 3 2022
A) \(\dfrac{1}{6}+\dfrac{7}{3}-\dfrac{1}{2}\)
Quy đồng:
\(\dfrac{7}{3}=\dfrac{14}{6}\)
\(\dfrac{1}{2}=\dfrac{3}{6}\)
\(\dfrac{1}{6}=\dfrac{1}{6}\)
\(\dfrac{1}{6}+\dfrac{14}{6}-\dfrac{3}{6}=\dfrac{12}{6}\)
Rút gọn: \(\dfrac{12}{6}=\dfrac{12\div6}{6\div6}=2\)
VN
Võ Ngọc Phương
VIP
11 tháng 9 2023
Bài 4:
a) \(\dfrac{4}{3}+\left(1,25-x\right)=2,25\)
\(1,25-x=2,25-\dfrac{4}{3}=\dfrac{9}{4}-\dfrac{4}{3}\)
\(1,25-x=\dfrac{11}{12}\)
\(x=1,25-\dfrac{11}{12}=\dfrac{5}{4}-\dfrac{11}{12}\)
\(x=\dfrac{1}{3}\)
b) \(\dfrac{17}{6}-\left(x-\dfrac{7}{6}\right)=\dfrac{7}{4}\)
\(x-\dfrac{7}{6}=\dfrac{17}{6}-\dfrac{7}{4}=\dfrac{34}{12}-\dfrac{21}{12}\)
\(x-\dfrac{7}{6}=\dfrac{13}{12}\)
\(x=\dfrac{13}{12}+\dfrac{7}{6}=\dfrac{13}{12}+\dfrac{14}{12}\)
\(x=\dfrac{27}{12}=\dfrac{9}{4}\)
c) \(4-\left(2x+1\right)=3-\dfrac{1}{3}=\dfrac{9}{3}-\dfrac{1}{3}\)
\(4-\left(2x+1\right)=\dfrac{8}{3}\)
\(2x+1=\dfrac{8}{3}+4=\dfrac{8}{3}+\dfrac{12}{3}\)
\(2x+1=\dfrac{20}{3}\)
\(2x=\dfrac{20}{3}-1=\dfrac{20}{3}-\dfrac{3}{3}\)
\(2x=\dfrac{17}{3}\)
\(x=\dfrac{17}{3}.\dfrac{1}{2}=\dfrac{17}{6}\)
Bài 15:
a) \(\left(\dfrac{-2}{3}\right)^9:x=\dfrac{-2}{3}\)
\(x=\left(\dfrac{-2}{3}\right)^9:\dfrac{-2}{3}=\left(\dfrac{-2}{3}\right)^{9-1}\)
\(=>x=\left(\dfrac{-2}{3}\right)^8\)
b) \(x:\left(\dfrac{4}{9}\right)^5=\left(\dfrac{4}{9}\right)^4\)
\(x=\left(\dfrac{4}{9}\right)^4.\left(\dfrac{4}{9}\right)^5=\left(\dfrac{4}{9}\right)^{4+5}\)
\(=>x=\left(\dfrac{4}{9}\right)^9\)
c) \(\left(x+4\right)^3=-125\)
\(\left(x+4\right)^3=\left(-5\right)^3\)
\(=>x+4=-5\)
\(x=-5-4\)
\(=>x=-9\)
d) \(\left(10-5x\right)^3=64\)
\(\left(10-5x\right)^3=4^3\)
\(=>10-5x=4\)
\(5x=10-4\)
\(5x=6\)
\(=>x=\dfrac{6}{5}\)
e) \(\left(4x+5\right)^2=81\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(4x+5\right)^2=\left(-9\right)^2\\\left(4x+5\right)^2=9^2\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}4x+5=-9\\4x+5=9\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}4x=-14\\4x=4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-14}{4}\\x=1\end{matrix}\right.\)
Bài 16:
a) \(4-1\dfrac{2}{5}-\dfrac{8}{3}\)
\(=4-\dfrac{7}{5}-\dfrac{8}{3}\)
\(=\dfrac{60-21-40}{15}=\dfrac{-1}{15}\)
b) \(-0,6-\dfrac{-4}{9}-\dfrac{16}{15}\)
\(=\dfrac{-3}{5}+\dfrac{4}{9}-\dfrac{16}{15}\)
\(=\dfrac{\left(-27\right)+20-48}{45}=\dfrac{-55}{45}=\dfrac{-11}{9}\)
c) \(-\dfrac{15}{4}.\left(\dfrac{-7}{15}\right).\left(-2\dfrac{2}{5}\right)\)
\(=\dfrac{7}{4}.\dfrac{-12}{5}\)
\(=\dfrac{-21}{5}\)
\(#Wendy.Dang\)
15 tháng 4 2022
a: =3/4-5/4+3/2x12/5=-1/2+36/10=-5/10+36/10=31/10
b: \(=\dfrac{-7}{13}\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{7}{13}+8=8\)
\(45:2\dfrac{4}{7}+50\%-1,25=45:\dfrac{18}{7}+\dfrac{50}{100}-\dfrac{125}{100}\\ =45.\dfrac{7}{18}+\dfrac{1}{2}-\dfrac{5}{4}\\ =\dfrac{35}{2}+\dfrac{1}{2}-\dfrac{5}{4}\\ =18-\dfrac{5}{4}=\dfrac{67}{4}\)