23/6 : x - 2/5 = 1/4 c
Bài 1 : a) x nhân 5 = 2 - 0,85
b) x - 5/6 : 1 1/6 = 0,125
c) 3/5 - 1/4 : x = 25/100
d) 23/45 x 15/16 x 32/23 + 0,3 nhân x
= 52/5 x 2/27 x 5/13
Mong m.n giúp e nhé !!!
Bài 1:Thực hiện phép tính :
a) 11 3/4 - ( 6 5/6 - 4 1/2) + 1 2/3
b)2 17/20 - 1 11/15 + 6 9/20 : 3
c) 4 3/7 : ( 7/5 x 4 3/7)
d)( 3 2/9 x 15/23 x 1 7/29) : 5/23
1) Tìm x
x - 35% . x = 1/25
2) Tính
a) 17 2/31 - ( 15/17 + 6 2/31 )
b) 27 51/59 - ( 25 51/29 - 1 1/3 )
c) ( 4 5/23 - 2 2/5 + 7 7/13 ) - ( 3 5/23 - 6 6/13 )
d) 8 1/3 + 7,8 + 5 2/3 - 1,8
Bài 1:
Ta có: \(x-35\%\cdot x=\dfrac{1}{25}\)
\(\Leftrightarrow65\%\cdot x=\dfrac{1}{25}\)
\(\Leftrightarrow x=\dfrac{1}{25}:\dfrac{13}{20}=\dfrac{1}{25}\cdot\dfrac{20}{13}=\dfrac{4}{65}\)
Vậy: \(x=\dfrac{4}{65}\)
Bài 2:
a) Ta có: \(17\dfrac{2}{31}-\left(\dfrac{15}{17}+6\dfrac{2}{31}\right)\)
\(=17\dfrac{2}{31}-\dfrac{15}{17}-6\dfrac{2}{31}\)
\(=11+\dfrac{2}{31}-\dfrac{15}{17}\)
\(=\dfrac{5366}{527}\)
Tìm x
a, 1/4+1/3:(2.x-1)=-5
b, 7/9:(2+3/4.x)+5/9=23/27
c, |2.x-1/3|+5/6=1
1/4+1/3:(2x-1)=-5
-->1/3:(2x-1)=-5-1/4
-->1/3:(2x-1)=-21/4
-->2x-1 =1/3:-21/4
-->2x-1 =-4/63
-->2x =-4/63+1
-->2x =59/63
--x =59/126
b7/9:(2+3/4x)+5/9=23/27
-->7/9:(2+3/4x) =23/27-5/9
-->7/9:(2+3/4x) =8/27
-->2+3/4x =7/9:8/27
-->2+3/4x =21/8
-->3/4x =21/8-2
-->3/4x =5/8
-->x =5/8:3/4
-->x =5/6
c|2x-1/3|+5/6=1
-->|2x-1/3| =1-5/6
-->|2x-1/3| =1/6
-->\(\orbr{\begin{cases}2x-\frac{1}{3}=\frac{1}{6}\\2x-\frac{1}{3}=-\frac{1}{6}\end{cases}}\)
-->\(\orbr{\begin{cases}2x=\frac{1}{6}+\frac{1}{3}\\2x=-\frac{1}{6}+\frac{1}{3}\end{cases}}\)
-->\(\orbr{\begin{cases}2x=\frac{1}{2}\\2x=\frac{1}{6}\end{cases}}\)
-->\(\orbr{\begin{cases}x=\frac{1}{2}:2\\x=\frac{1}{6}:2\end{cases}}\)
-->\(\orbr{\begin{cases}x=\frac{1}{4}\\x=\frac{1}{12}\end{cases}}\)
Giá trị x thoả mãn \(2\dfrac{1}{4}x - 6\dfrac{3}{5} = 3,75 \) là :
A. \(\dfrac{4}{5}\) B. \(\dfrac{23}{5}\)
C.\(\dfrac{13}{5}\) D. \(\dfrac{1}{7}\)
Bài 2. Tính bằng cách thuận tiện nhất.
( 2/3 x 4/5 ) x 5/6
(4/5 + 5/4 ) x 3/4
11/23 + 2/23 + 9/23 + 18/23
27/12 + 17/6 - 25/36 - 15/6
TL:
8/15 x 5/6 = 40/90 = 4/9
41/20 x 3/4 = 123/80
(11/23 + 9/23) + (18/23 + 2/23) = 20/23 + 20/23 = 40/43
HT
\(\left(\frac{2}{3}\times\frac{4}{5}\right)\times\frac{5}{6}\) = \(\frac{2}{3}\times\frac{4}{5}\times\frac{5}{6}\)=\(\frac{2\times4\times5}{3\times5\times6}\)=\(\frac{2\times4\times5}{3\times5\times2\times3}\)=\(\frac{4}{9}\)
\(\frac{11}{23}+\frac{2}{23}+\frac{9}{23}+\frac{18}{23}\)=\(\frac{\left(11+9\right)+\left(18+2\right)}{23}\)=\(\frac{20+20}{23}\)=\(\frac{40}{23}\)
\(\frac{27}{12}+\frac{17}{6}-\frac{25}{36}-\frac{15}{6}\)=\(\left(\frac{27}{12}-\frac{25}{36}\right)+\left(\frac{17}{6}-\frac{15}{6}\right)\)=\(\frac{14}{9}+\frac{2}{6}\)=\(\frac{17}{9}\)
/HT\
Nhập các bạn toàn bắt tớ làm à ngu gò mà làm
TÌM X: các bạn giải hộ mình nha
a) 3x-1= (-7) b)(-23)-3(x-5)=(-5)=(-5).(-2)
c)(x-4).(2x+6)=0
c)(x-4).(2x+6)=0
=>(x-4)=0 hoặc (2x+6)=0
với x-4 = 0
x =0+4
x =4
với 2x+6=0
2x =0-6
2x =-6
x =-6:2
x =-3
c) 7/23 x [(-8/6) - 45/18]
d) 23 1/4 : 7/5 - 13 1/4 : 5/7
e) 25 x 153 / 63 x 102
l) (1/3)10 x (9)25 - (2/3)10 : (4/9)5
i) (-5)7 x (-1/5)7 + 0.56 x (-2)6
A)2/5+3/5.(3.x-3,7)=-53/10
b)7/9:(2+3/4.x)+5/9=23/27
c)|2.x-1/3|+5/6=1
a)<=>10+15(3x-3,7)=-5,3
<=>10+45x-55,5=-5,3
<=>45x-45,5=-5,3
<=>45x=40,2
<=>x=\(\frac{40,2}{45}\)
b)