\(\left(4,5-2.x\right).1\frac{4}{7}=\frac{11}{14}\)
Tìm x biết
\(a,\left[20\%x+\frac{2}{5}x-2\right]\div\frac{1}{3}=2013\)
\(b,\left[4,5-2\left|x\right|\right]\times1\frac{4}{7}=\frac{11}{14}\)
bài 1
\(\frac{2}{3}x-\frac{4}{9}=\frac{2}{9}\)
(4,5 - 2x). \(\left[-1\frac{4}{7}\right]=\frac{11}{14}\)
a) 2/3 x = 2/9 + 4/9
=> 2/3 x = 2/3
=> x = 1
b) 4,5 - 2x = 11/14 + \(-1\frac{4}{7}\)
=> 4,5 - 2x = 5/14
=> 2x = 4,5 - 5/14
=> 2x = 29/7
=> x= 29/14
Tìm x:
a, x + 30%x = -1,31
b,\(\left(x-\frac{1}{2}\right):\frac{1}{3}+\frac{5}{7}=9\frac{5}{7}\)
c, \(\frac{1}{2}x-\frac{3}{4}=\frac{14}{9}.\frac{3}{7}\)
d,\(\frac{-5}{6}-x=\frac{7}{12}+\frac{-1}{3}\)
e,\(\frac{x+3}{-15}=\frac{1}{3}\)
f,\(\left(4,5-2x\right).\left(-1\frac{4}{7}\right)=\frac{11}{14}\)
GIÚP MIK LM TRONG TỐI NAY NHA, MAI MIK PHẢI NỘP RỒI
\(a)x+30\%x=-1,31\)
\(\Leftrightarrow x+\frac{3x}{10}=-1,31\)
\(\Leftrightarrow10x+3x=-13,1\)
\(\Leftrightarrow13x=-13,1\Leftrightarrow x=-\frac{131}{130}\)
\(b)\left(x-\frac{1}{2}\right):\frac{1}{3}+\frac{5}{7}=9\frac{5}{7}\)
\(\Leftrightarrow\frac{2x-1}{2}.3+\frac{5}{7}=\frac{68}{7}\)
\(\Leftrightarrow\frac{6x-3}{2}=\frac{63}{7}\)
\(\Leftrightarrow\frac{6x-3}{2}=9\)
\(\Leftrightarrow6x-3=18\)
\(\Leftrightarrow x=\frac{7}{2}\)
\(c)\frac{1}{2}x-\frac{3}{4}=\frac{14}{9}.\frac{3}{7}\)
\(\Leftrightarrow\frac{x}{2}-\frac{3}{4}=\frac{2}{3}\)
\(\Leftrightarrow\frac{x}{2}=\frac{17}{12}\)
\(\Leftrightarrow12x=34\Leftrightarrow x=\frac{17}{6}\)
Tìm x biết
\(2\frac{x}{7}=\frac{75}{35}\)
\(\left(4,5-2x\right).\frac{14}{7}=\frac{11}{4}\)
\(\left(4,5-2x\right).\frac{14}{7}=\frac{11}{4}\)
\(4,5-2x=\frac{11}{4}:\frac{14}{7}\)
\(4,5-2x=\frac{77}{56}\)
\(2x=\frac{77}{56}+4,5\)
\(2x=\frac{77}{56}+\frac{9}{2}\)
\(2x=\frac{329}{56}\)
Biết \(\left(4,5-2x\right).\frac{11}{7}=\frac{11}{14}\)
Khi đó x = ..........?
\(\left(4,5-2x\right).\frac{11}{7}=\frac{11}{14}\)
\(4,5-2x=\frac{11}{14}.\frac{7}{11}=\frac{1}{2}\)
\(2x=\frac{1}{2}-4,5=-4\)
\(x=\left(-4\right):2=-2\)
Bài 1: Thực hiện phép tính bằng cách hợp lí ( nếu có thể )
a, \(-\frac{4}{5}-\frac{8}{25}\left(\frac{-5}{2}-0,125\right)\) c, \(5\frac{1}{2}-4\frac{2}{3}:\frac{16}{9}-3\frac{1}{3}:\frac{16}{9}\) Bài 2: Tìm x, biết
a, \(\left(20\%x+\frac{2}{5}x-2\right):\frac{1}{3}=-2013\) b, \(\left(4,5-2\left|x\right|\right).1\frac{4}{7}=\frac{11}{14}\)
HELP ME!
Bài 1:
a) \(-\frac{4}{5}-\frac{8}{25}\left(\frac{-5}{2}-0,125\right)\\ =-\frac{4}{5}-\frac{8}{25}\left(\frac{-5}{2}-\frac{1}{8}\right)\\ =-\frac{4}{5}-\frac{8}{25}\left(\frac{-20}{8}-\frac{1}{8}\right)\\ =-\frac{4}{5}-\frac{8}{25}\cdot\frac{-21}{8}\\ =-\frac{4}{5}-\frac{-21}{25}\\ =\frac{-4}{5}+\frac{21}{25}\\ =\frac{-20}{25}+\frac{21}{25}=\frac{1}{25}\)
c) \(5\frac{1}{2}-4\frac{2}{3}:\frac{16}{9}-3\frac{1}{3}:\frac{16}{9}\\ =5\frac{1}{2}-\left(4\frac{2}{3}:\frac{16}{9}+3\frac{1}{3}:\frac{16}{9}\right)\\ =5\frac{1}{2}-\left(4\frac{2}{3}+3\frac{1}{3}\right):\frac{16}{9}\\ =5\frac{1}{2}-8\cdot\frac{9}{16}\\ =\frac{11}{2}-\frac{9}{2}=\frac{2}{2}=1\)
Bài 2:
a) \(\left(20\%x+\frac{2}{5}x-2\right):\frac{1}{3}=-2013\\ \left(\frac{1}{5}x+\frac{2}{5}x-2\right)\cdot3=-2013\\ \left[x\left(\frac{1}{5}+\frac{2}{5}\right)-2\right]=\left(-2013\right):3\\ x\cdot\frac{3}{5}-2=-671\\ x\cdot\frac{3}{5}=-671+2\\ x\cdot\frac{3}{5}=-669\\ x=\left(-669\right):\frac{3}{5}\\ x=\left(-669\right)\cdot\frac{5}{3}\\ x=-1115\)Vậy x = -1115
b) \(\left(4,5-2\left|x\right|\right)\cdot1\frac{4}{7}=\frac{11}{14}\\ \left(\frac{9}{2}-2\left|x\right|\right)\cdot\frac{11}{7}=\frac{11}{14}\\ \frac{9}{2}-2\left|x\right|=\frac{11}{14}:\frac{11}{7}\\ \frac{9}{2}-2\left|x\right|=\frac{11}{14}\cdot\frac{7}{11}\\ \frac{9}{2}-2\left|x\right|=\frac{1}{2}\\ 2\left|x\right|=\frac{9}{2}-\frac{1}{2}\\ 2\left|x\right|=4\\ \left|x\right|=4:2\\ \left|x\right|=2\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)Vậy x ∈ {2 ; -2}
tìm x
\(|x+3|\div\left(-15\right)=\frac{1}{3}\)
\(|4,5-2x|\cdot(-1\frac{4}{7})=\frac{-11}{14}\)
giúp mình với mai mình nộp rồi
a) \(\left|x+3\right|:\left(-15\right)=\frac{1}{3}\)
\(\left|x+3\right|=-5\)
=> không tìm được x
b) \(\left|4,5-2x\right|.\left(-1\frac{4}{7}\right)=-\frac{11}{14}\)
\(\left|4,5-2x\right|=2\)
TH1: 4,5 - 2x = 2
2x = 2,5
x = 1,25
TH2: 4,5 - 2x = -2
2x = 6,5
x = 3,25
KL:...
\(\left(4,5-2x\right).\left(-3\frac{2}{3}\right)=\frac{11}{15}\)
\(\backslash34-x\backslash=\left(-3\right)^4\)
\(\left(4x^2-1\right)\left(\backslash x\backslash-\frac{2}{3}\right)=0\)
\(\frac{3}{5}x-\frac{1}{2}x=\frac{-7}{2}\)
Tính:
A=\(\left(1-\frac{2}{3}+\frac{4}{3}\right)-\left(\frac{4}{5}-1\right)+\left(\frac{7}{5}+2\right)\)
B=\(\left(-3+\frac{3}{4}-\frac{1}{3}\right):\left(5+\frac{2}{5}-\frac{2}{3}\right)\)
C=\(\left(\frac{3}{5}-\frac{4}{15}\right).\left(\frac{2}{7}-\frac{3}{14}\right)-\left(\frac{5}{9}-\frac{7}{27}\right)\)\(.\left(1-\frac{3}{5}\right)+\left(1-\frac{11}{12}\right).\left(1+\frac{11}{12}\right)\)
D=\(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{-5}{19}}{\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\frac{4}{3}}\)