Tìm x biết (1-3/10-x):(19/10- 1- 2/5)+ 4/5= 1
tìm x biết
(3-9/10-|x+2|):(19/10-1-2/5)+4/5=1
\(\left(3-\frac{9}{10}-\left|x+2\right|\right):\left(\frac{19}{10}-1-\frac{2}{5}\right)+\frac{4}{5}=1\)
\(\left(\frac{21}{10}-\left|x+2\right|\right):\frac{1}{2}+\frac{4}{5}=1\)
\(\left(\frac{21}{10}-\left|x+2\right|\right):\frac{1}{2}=\frac{1}{5}\)
\(\frac{21}{10}-\left|x+2\right|=\frac{1}{10}\)
=> |x+2| = 2
TH1: x + 2 = 2 => x = 0
TH2: x + 2 = -2 => x = -4
KL:...
Bài tìm x biết
a) x/5 = 5/6+ -19/30
b)x-4 1/5=-2/3
c) 3 1/5-x=1 1/3+7/10
d) 9/x=2/5+-7/20
a)\(\frac{X}{5}=\frac{5}{6}+\frac{-19}{30}\)
\(\frac{X}{5}=\frac{1}{5}\)
Vậy \(X=1\)
b)\(X-\frac{41}{5}=\frac{-2}{3}\)
\(X=\frac{-2}{3}+\frac{41}{5}\)
\(X=\frac{113}{15}\)
Vậy \(X=\frac{113}{15}\)
c)\(\frac{31}{5}-X=\frac{11}{3}+\frac{7}{10}\)
\(\frac{31}{5}-X=\frac{131}{30}\)
\(X=\frac{31}{5}-\frac{131}{30}\)
\(X=\frac{11}{6}\)
Vậy \(X=\frac{11}{6}\)
d)\(\frac{9}{X}=\frac{2}{5}+\frac{-7}{20}\)
\(\frac{9}{X}=\frac{1}{20}\)
\(X=9:\frac{1}{20}\)
\(X=180\)
Vậy \(X=180\)
Hc tốt
1) Tìm x biết:
\(\left(1-\dfrac{3}{10}-x\right):\left(\dfrac{19}{10}-1-\dfrac{2}{5}\right)+\dfrac{4}{5}=1\)
2) Tính nhanh
a)\(\dfrac{1}{1.2.3}+\dfrac{1}{2.3.4}+\dfrac{1}{3.4.5}+...+\dfrac{1}{10.11.12}\)
b)\(\dfrac{1^2}{1.2}.\dfrac{2^2}{2.3}.\dfrac{3^2}{3.4}.\dfrac{4^2}{4.5}\)
câu b bài 2:
\(\dfrac{1^2}{1\cdot2}\cdot\dfrac{2^2}{2\cdot3}\cdot\dfrac{3^2}{3\cdot4}\cdot\dfrac{4^2}{4\cdot5}\)
\(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot\dfrac{3}{4}\cdot\dfrac{4}{5}\)
\(=\dfrac{1}{5}\)
câu a bài 2:
\(\dfrac{1}{1\cdot2\cdot3}+\dfrac{1}{2\cdot3\cdot4}+\dfrac{1}{3\cdot4\cdot5}+...+\dfrac{1}{10\cdot11\cdot12}\)
\(=\dfrac{1}{1}-\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{4}-...-\dfrac{1}{12}\)
\(=1-\dfrac{1}{12}=\dfrac{11}{12}\)
Tìm x thuộc Z biết :
a, -19/6 + -15/2 + 11/3 < x < hoặc = -5/4 + 19/12 + -10/3
b, 1/3 + -2/5 + 1/6 + -1/5 < hoặc = x < -3/4 + 2/7 + -1/4 + 3/5 + 5/7
P/S : dấu / là phân số nhé
Tìm x thuộc Z biết :
a, -19/6 + -15/2 + 11/3 < x < hoặc = -5/4 + 19/12 + -10/3
b, 1/3 + -2/5 + 1/6 + -1/5 < hoặc = x < -3/4 + 2/7 + -1/4 + 3/5 + 5/7
P/S : dấu / là phân số nhé
Tìm x:
( 1 - 3/10 - x ) : ( 19/10 - 1 - 2/ 5 ) + 4/5 = 1
Các bạn giải nhanh giúp mk nha!!!
( 1 - 3/10 - x ) : ( 19/10 - 1 - 2/ 5 ) + 4/5 = 1
=> (7/10 - x) : (9/10 - 2/5) = 1 - 4/5
=> (7/10 - x) : 1/2 = 3/5
=> (7/10 - x) = 3/5 : 1/2
=> 7/10 - x = 6/5
=> x = 7/10 - 6/5
=> x = -1/2
ko ghi lại đề
=>(7/10-x):1/2+4/5=1
=>(7/10-x):1/2=1/5
=>7/10-x=1/10
=>x=3/5
( 1 - 3 / 10 - x ) : ( \(\frac{19}{10}\)- 1 - \(\frac{2}{5}\)) + \(\frac{4}{5}\)= 1
=> ( \(\frac{7}{10}\)- x ) : \(\frac{1}{2}\)+ \(\frac{4}{5}\)= 1
=> ( \(\frac{7}{10}\)- x ) : \(\frac{1}{2}\)= \(\frac{1}{5}\)
=> \(\frac{7}{10}\)- x = \(\frac{1}{10}\)
=> x = \(\frac{3}{5}\)
tìm x biết:
1) 14- (5-8+3-x) = |-7+10|
2) -19 - ?(3+x-5) = |4-15+2|
3) 45- (x+45-3) = |-7+3|
Bài 1: Tính
a) 1/3 + 1/5 - 1/4 b) 7/8 - ( 1/4 + 2/5 ) c) 5/11 - ( 3/5 - 6/11 )
Bài 2: Tìm x
a) x + 2/5 = 1/2 b) x + 3/7 = 2/5 + 3/10 c) 19/20 - x = 8/5 - 3/4
Bài 3: Tìm số tự nhiên x, biết:
a ) 4/7 < x < 1/2 + 10/3 b) 3/10 + 8/5 < x < 2/5 + 5
Giúp mình nha ^^ Ai nhanh mình Tick !!!!!!!!!❤❤