Tìm x :
a) x.3 - x : 3 = 36,5.4
b) (x + 1 ) + (x + 4 ) + ( x + 7 ) + ... + ( x + 28 ) = 156
c) 11 .( x - 6 ) = ( 4.x ) + 11.
Tìm x, biết:
a, 11/13 - ( 5/42 -x ) = - ( 5/28 - 11/13 )
b, | x + 4/15 | - | - 3,75 | = -| -2,15 |
c, ( 0,25 - 30% x ) . 1/3 = 1/4 - 31/6
d, ( x - 1/2 ) : 1/3 + 5/7 = 68/7
a, 11/13 - ( 5/42 - x ) = - (5/28 - 11/13)
11/13 - (5/42 - x) = - 5/28 + 11/13
- (5/42 - x) + 5/28 = -11/13 + 11/13
- 5/42 + x + 5/28 = 0
- 5/42 + x = 0 - 5/28
- 5/42 + x = - 5/28
x = -5/28 +5/42
x = - 5/84
b, / x + 4/15 \ - / - 3,75 \ = - / - 2,15 \
./ x + 4/15 \ - 3,75 = - 2,15
/ x + 4/15 \ = -2,15 + 3,75
/ x + 4/15 \ = 1,6
x + 4 / 15 = 1,6 hoặc x+ 4/15 = - 1,6
x = 1,6 - 4/15 x = - 1,6 -4/15
x = 4/3 x = -28/15
Vậy x = 4/3 hoặc x = - 28/15
c, ( 0,25 - 30% x ) . 1/3 = 1/4 - 31/6
( 1/4 - 3/10 x ) . 1/3 = - 59/12
( 1/4 - 3/10 x ) = - 59/12 : 1/3
1/4 - 3/10 x = - 59/4
3/10 x = 1/4 + 59/4
3/10 x = 15
x = 15 : 3/10
x = 50
d, ( x - 1/2 ) : 1/3 + 5/7 = 68/7
( x - 1/2 ) : 1/3 = 68/7 - 5/7
( x - 1/2 ) : 1/3 = 63/7
( x - 1/2 ) = 63/7 . 1/3
x -1/2 = 3
x = 3 + 1/2
x = 7/2
Tìm x
a) 1/2 : 3 + x = 14/5
b) 8/5 : x : 7/4 = 11/6
c) 24/10 + x : 3/4 = 11/3
\(a.\dfrac{1}{2}:3+x=\dfrac{14}{5}\)
\(\dfrac{1}{6}+x=\dfrac{14}{5}\)
\(=>x=\dfrac{79}{30}\)
\(b.\dfrac{8}{5}:x:\dfrac{7}{4}=\dfrac{11}{6}\)
\(\left(\dfrac{8}{5}\cdot\dfrac{4}{7}\right):x=\dfrac{11}{6}\)
\(\dfrac{32}{35}:x=\dfrac{11}{6}\)
\(x=\dfrac{192}{385}\)
\(c.\dfrac{24}{10}+x:\dfrac{3}{4}=\dfrac{11}{3}\)
\(x:\dfrac{3}{4}=\dfrac{11}{3}-\dfrac{24}{10}\)
\(x:\dfrac{3}{4}=\dfrac{38}{30}\)
\(=>x=\dfrac{19}{20}\)
\(a,\dfrac{1}{2}:3+x=\dfrac{14}{5}\\ \Leftrightarrow x+\dfrac{1}{6}=\dfrac{14}{5}\\ \Leftrightarrow x=\dfrac{79}{30}\\ b,\dfrac{8}{5}:x:\dfrac{7}{4}=\dfrac{11}{6}\\ \Leftrightarrow x=\dfrac{192}{385}\\ c,\dfrac{24}{10}+x:\dfrac{3}{4}=\dfrac{11}{3}\\ \Leftrightarrow\dfrac{4}{3}x=\dfrac{19}{15}\\ \Leftrightarrow x=\dfrac{19}{20}\)
a 1/6+x=14/5
x=14/5-1/6
x= 79/30
b 8/5:x=11/6*7/4
8/5:x=77/24
x=77/24:8/5
x=385/192
c x:3/4=11/3-24/10
x:3/4=19/5
x=19/5*3/4
x=57/20
bài 1:tìm x biết
a) x + 1/9 - 3/5= 3/6 b) 3/4 - x + 6/-11 = 5/6
bài 2: tìm x biết
a) x : 13/16= 5/-8 b) x . -14/28 = 6/-9 - 2/15
c) -12/25 . (3/4 -x + 6/-11 - 5/6) = 0 d) x: 4/28 = 13/-19 + 8/25
bài 3:tìm x biết
a) 62/7.x= 29/9:3/56 b) 1/5:x=1/5+1/7 c)1/2a2+1 : x=2
Tìm x
A. 5 (x - 11) + 4(x -3) = 10
B. 21- 5 (x -7) = 2- 3 (x-5)
C. 3 (2x - 1) - 7(x +4) = 8-9x
D. | 4 - x | = 11
E. 5 - 3 | x+2| = -28
Trình bày cách làm luôn ạ
Mình cảm ơn
A. 5(x-11) + 4(x-3) =10
<=>5x -55 + 4x -12 =10
<=>9x -67 =10
<=>9x =10+67 =77
<=>x =77 : 9 =77/9
B.21 - 5 ( x-7) = 2-3(x-5)
<=>21-5x+35 = 2 - 3x +15
<=>-5x + 56 = -3x + 17
<=>-5x +3x=17-56=-39
<=> -2x =-39
<=> x = -39 : -2 =39/2
C.3(2x-1)-7(x+4)=8-9x
<=>6x -4 -7x-28=-9x+8
<=>-x + 9x = 8+4+28=40
<=> 8x = 40
<=> x = 40:8=5
D. l 4-x l =11
<=>\(\orbr{\begin{cases}4-x=11\\4-x=-11\end{cases}}\)<=> \(\orbr{\begin{cases}x=-7\\x=15\end{cases}}\)
E. 5-3 l x+2 l = -28
<=> 3 l x+2 L = -28 -5 =-33
<=> l x+2 l = -33 :3 =11
<=>\(\orbr{\begin{cases}x+2=11\\x+2=-11\end{cases}}\)<=> \(\orbr{\begin{cases}x=9\\-13\end{cases}}\)
T I C K mk nhé!!!^_^
bài 2 . thực hiện phép tính
a. -1,75-(-1/9-2 1/18)
b. -1/12- (2 5/8-1/3)
c. -5/6-(-3/8+1/10)
Bài 3 :tìm x ,biết :
a. 11/13-(5/42-x)=(-15/28-11/13)
b. x+1/3=2/5-(-1/3)
c. 3/7-x=1/4-(-3/5)
a.-1,75-(-\(\dfrac{1}{9}\)-2\(\dfrac{1}{8}\))
-1,75-\(\dfrac{1}{9}+\dfrac{17}{8}\)
\(-\dfrac{7}{4}-\dfrac{1}{9}+\dfrac{17}{8}\)
\(\dfrac{-126}{72}-\dfrac{8}{72}+\dfrac{153}{72}\)
=\(\dfrac{19}{72}\)
b.\(\dfrac{-1}{12}-\left(2\dfrac{5}{8}-\dfrac{1}{3}\right)\)
\(\dfrac{-1}{12}-\left(\dfrac{21}{8}-\dfrac{1}{3}\right)\)
\(\dfrac{-1}{12}-\dfrac{21}{8}+\dfrac{1}{3}\)
\(\dfrac{-2}{24}-\dfrac{63}{24}+\dfrac{64}{24}\)
=\(\dfrac{-1}{24}\)
\(\dfrac{-5}{6}-\left(\dfrac{-3}{8}+\dfrac{1}{10}\right)\)
\(\dfrac{-5}{6}-\dfrac{-3}{8}-\dfrac{1}{10}\)
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15
1: x=3/4-1/2=3/4-2/4=1/4
2: x-1/5=2/11
=>x=2/11+1/5=21/55
3: x-5/6=16/42-8/56
=>x-5/6=8/21-4/28=5/21
=>x=5/21+5/6=15/14
4: x/5=5/6-19/30
=>x/5=25/30-19/30=6/30=1/5
=>x=1
5: =>|x|=1/3+1/4=7/12
=>x=7/12 hoặc x=-7/12
6: x=-1/2+3/4
=>x=3/4-1/2=1/4
11: x-(-6/12)=9/48
=>x+1/2=3/16
=>x=3/16-1/2=-5/16
1)x= 1/4
2)x= 2/11+ 1/5
x= 21/55
3)x - 5/6 = 5/21
x = 5/21+5/6
x = 15/14
4)x/5 = 5/6 + -19/30
x:5 = 1/5
x = 1/5.5
x = 1
5) |x| - 1/4 = 6/18
|x| = 6/18 - 1/4
|x| =7/12
⇒x= 7/12 hoặc -7/12
6)x = -1/2 +3/4
x= 1/4
7) x/15 = 3/5 + -2/3
x:15 = -1/15
x = -1/15. 15
x = -1
8)11/8 + 13/6 = 85/x
85/24 = 85/x
⇒ x = 24
9) x - 7/8 = 13/12
x = 13/12 + 7/8
x = 47/24
10)x - -6/15 = 4/27
x = 4/27 + (-6/15)
x = -34/135
11) -(-6/12)+x = 9/48
x= 9/48 - 6/12
x = -5/16
12) x - 4/6 = 5/25 + -7/15
x -4/6 = -4/15
x = -4/15 + 4/6
x = 2/5
Bài 1 : Tính bằng hai cách
a) ( 6/11 + 5/11 ) x 3/7 =
b) 3/5 x 7/9 - 3/5 x 2/9 =
c) ( 6/7 - 4/7 ) : 2/5 =
d) 8/15 : 2/11 + 7/15 : 2/11 =
Bài 2 : Tính
a) 2 x 3 x4/3 x 4 x 5 =
b) 2/3 x 3/4 x 4/5 : 1/5 =
c) 1 x 2 x 3 x 4 / 5 x 6 x 7 x8 =
d) 2/5 x 3/4 x 5/6 : 3/4 =
a,Cách 1: (6/11 + 5/11 ) x 3/7 Cách 2 :(6/11 + 5/11) x 3/7
= 1 x 3/7 =6/11 x 3/7 + 5/11 x 3/7
= 3/7 = 18/77 + 15/77
= 3/7
b, Cách 1:3/5 x 7/9 - 3/5 x 2/9 Cách 2 :3/5 x 7/9 - 3/5 x 2/9
= 7/15 - 2/15 = 3/5 x (7/9 - 2/9 )
= 1/3 = 3/5 x 5/9
= 1/3
c, Cách 1:(6/7 - 4/7) : 2/5 Cách 2: ( 6/7- 4/7 ) : 2/5
= 2/7 : 2/5 = 6/7 : 2/5 - 4/7 : 2/5
= 5/7 = 15/7 - 10/7
= 5/7
d,Cách 1:8/15 : 2/11 + 7/15 : 2/11 Cách 2:8/15 : 2/11 +7/15 : 2/11
= 88/30 + 77/30 =(8/15+7/15) :2/11
= 11/2 = 1 : 2/11
= 11/2
Bài 2 cậu tự làm nhé !
\(2a.160\)
\(b.2\)
\(c.\frac{8064}{5}\)
\(d.\frac{1}{3}\)
A) ( 2/5× 1/2)×3/8 =?
B)7/9 ×3/5 + 4/9 ÷3/5=?
bài 1:tìm x biết
a) x + 1/9 - 3/5= 3/6 b) 3/4 - x + 6/-11 = 5/6
bài 2: tìm x biết
a) x : 13/16= 5/-8 b) x . -14/28 = 6/-9 - 2/15
c) -12/25 . (3/4 -x + 6/-11 - 5/6) = 0 d) x: 4/28 = 13/-19 + 8/25
bài 3:tìm x biết
a) 62/7.x= 29/9:3/56 b) 1/5:x=1/5+1/7 c)1/2a2+1 : x=2
Bài 1:
a) x + 19 - 35 = 36 b) 34 - x + 611 = 56
x + 19 = 36 + 35 34 - x = 56 - 611
x + 19 = 1110 34 - x = 1966
x = 1110 - 19 x =
Bài 1 Tìm x,biết
x.3/5=2/3
x.7/17=17/8
3/4 chia x=-7/12
3/8 - 1/6.x=1/4
1/3+1/2 chia x=-4
Bài 2 Tính
-6/11 chia [3/5 . 4/11]
7/12 + 5/12 chia 6 -11/36
[4/5 + 1/2] chia [3/13 - 8/13]
[2/3 - 1/4 + 5/11] chia [5/12 + 1 -7/11]
*Dấu . là dấu nhân nha mn*
Bài 1:
a: \(x=\dfrac{2}{3}:\dfrac{3}{5}=\dfrac{2}{3}\cdot\dfrac{5}{3}=\dfrac{10}{9}\)
b: \(x=\dfrac{17}{8}:\dfrac{7}{17}=\dfrac{17}{8}\cdot\dfrac{17}{7}=\dfrac{289}{56}\)
c: \(x=-\dfrac{3}{4}:\dfrac{7}{12}=\dfrac{-3}{4}\cdot\dfrac{12}{7}=\dfrac{-63}{28}=-\dfrac{9}{4}\)
d: \(\Leftrightarrow x\cdot\dfrac{1}{6}=\dfrac{3}{8}-\dfrac{1}{4}=\dfrac{1}{4}\)
hay \(x=\dfrac{1}{4}:\dfrac{1}{6}=\dfrac{3}{2}\)
e: \(\Leftrightarrow\dfrac{1}{2}:x=-4-\dfrac{1}{3}=-\dfrac{17}{3}\)
hay \(x=-\dfrac{1}{2}:\dfrac{17}{3}=\dfrac{-3}{34}\)