Tìm x thuộc Q, biết:
11/12 - ( 2/5 + x)=2/52x (x-1/7) = 03/4 + 1/4 : x=2/5Tìm x thuộc Q, biết:
11/12 - ( 2/5 + x)=2/52x (x-1/7) = 03/4 + 1/4 : x=2/51. 2/5 + x= 11/12 - 2/5
=> x= 31/60 - 2/5
=> x= 7/60
Vậy x= 7/60
2. 2x(x - 1/7)= 0
TH1: x=0
TH2: x= 0 + 1/7 = 1/7
Vậy x= 0 hoặc 1/7
3. 1/4 : x= 2/5 - 3/4
=> x= 1/4 : (-7/20)
=> x= -5/7
Vậy x= -5/7
tìm x thuộc Q biết rằng :
a) 11/12 - ( 2/5 + x ) = 2/3
b) 2x ( x - 1/7) =0
c) 3/4 + 1/4 :x =2/5
Mọi người ơi tk mình đi mình đang bị âm điểm nè !
hahahahaha................................................................hihihihihihihihihihihihahahahahahahahahahihihihiha đ c m
Tìm x thuộc Q biết rằng:
a) 11/12 - (2/5 + x) = 2/3
b) 2.x (x - 1/7) = 0
c) 3/4 + 1/4 : x = 2/5
a) 11/12-(2/5+x)=2/3
=>2/5+x=11/12-2/3
=>2/5+x=1/4
=>x=1/4-2/5
=>x=-3/20
b) 2.x(x-1,7)=0
=>x(x-1,7)=0
=>x= 0 hoặc x-1,7=0
=>x=0 hoặc x= 1,7
3/4+1/4:x=2/5
=>1/4:x=2/5-3/4
=>1/4:x=-7/20
=>x=1/4:-7/20
=>x=-5/7
Tìm x thuộc Q biết rằng
a, 11/12-(2/5+x) = 2/3
b, 2x.(x-1/7)=0
c,3/4+1/4:x=2/5
a)\(\frac{11}{12}-\left(\frac{2}{5}+x\right)=\frac{2}{3}\)
<=>\(\frac{11}{12}-\frac{2}{5}-x=\frac{2}{3}\)
<=>\(-x=\frac{2}{3}-\frac{11}{12}+\frac{2}{5}\)
<=>\(-x=\frac{3}{20}\)
<=>\(x=-\frac{3}{20}\)
b)\(2x\left(x-\frac{1}{7}\right)=0\)
<=>2x=0 hoặc \(x-\frac{1}{7}=0\)
<=>x=0 hoặc x=\(\frac{1}{7}\)
c)\(\frac{3}{4}+\frac{1}{4}:x=\frac{2}{5}\)
<=>\(\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)
<=>\(\frac{1}{4}:x=-\frac{7}{20}\)
<=>\(x=\frac{1}{4}:\left(-\frac{7}{20}\right)\)
<=>\(x=-\frac{5}{7}\)
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 \(x=-\dfrac{1}{2}:\dfrac{17}{3}=\dfrac{-3}{34}\)
tìm x \(\in\) Q biết rằng
\(\dfrac{11}{12}\) - ( \(\dfrac{2}{5}\) + x ) = \(\dfrac{2}{3}\)
2x \(\times\) ( x - \(\dfrac{1}{7}\) ) = 0
\(\dfrac{3}{4}\) + \(\dfrac{1}{4}\) : x = \(\dfrac{2}{5}\)
1) \(\dfrac{11}{12}-\left(\dfrac{2}{5}+x\right)=\dfrac{2}{3}\)
\(\Leftrightarrow\dfrac{11}{12}-\dfrac{2}{5}-x=\dfrac{2}{3}\)
\(\Leftrightarrow x=\dfrac{11}{12}-\dfrac{2}{5}-\dfrac{2}{3}\)
\(\Leftrightarrow x=-\dfrac{3}{20}\)
2) \(2x\left(x-\dfrac{1}{7}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x=0\\x-\dfrac{1}{7}=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{7}\end{matrix}\right.\)
3) \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
\(\Leftrightarrow\dfrac{1}{4x}=\dfrac{2}{5}-\dfrac{3}{4}\)
\(\Leftrightarrow\dfrac{1}{4x}=-\dfrac{7}{20}\)
\(\Leftrightarrow4x=-\dfrac{20}{7}\)
\(\Leftrightarrow x=-\dfrac{5}{7}\)
tìm x thuộc Q, biết rằng :
a) 11/120- (2/5+x) =2/3
b) 2x.(x-1/7) = 0
c) 3/4 + 1/4 : x = 2/5
Tìm x biết
1) 2.(x +5)+3.(x+7)=41. 6) 7. (x -1)+5.(3-x)=11.x-10
2) 5. ( x +6 ) +2.(x-3)=38. 7) 4. (2+x)+3(x-2)=12
3) 7.(5+x)+2.(x-10)=15. 8) 5. ( 2+x) +4.(3-x)=10x-15
4) 3. (x+4)+(8-2.x) =22. 9) 7.(x-2) +5.(3-x)=11x-6
5) 4. (x+5)+3.(7-x)=49. 10) 5.(3-x)+5.(x+4)=6+4x
1) 2(x + 5) + 3(x + 7) = 41
2x + 10 + 3x + 21 = 41
5x + 31 = 41
5x = 10
x = 2
6) 7(x - 1) + 5(3 - x) = 11x - 10
7x - 7 + 15 - 5x = 11x - 10
2x + 8 = 11x - 10
-9x = -18
x = 2
2) 5(x + 6) + 2(x - 3) = 38
5x + 30 + 2x - 6 = 38
7x + 24 = 38
7x = 14
x = 2
7) 4(2 + x) + 3(x - 2) = 12
8 + 4x + 3x - 6 = 12
7x + 2 = 12
7x = 10
x = 10/7
3) 7(5 + x) + 2(x - 10) = 15
35 + 7x + 2x - 20 = 15
9x + 15 = 15
9x = 0
x = 0
8) 5(2 + x) + 4(3 - x) = 10x - 15
10 + 5x + 12 - 4x = 10x - 15
x + 22 = 10x - 15
9x = 37
x = 37/9
4) 3(x + 4) + (8 - 2x) = 22
3x + 12 + 8 - 2x = 22
x + 20 = 22
x = 2
9) 7(x - 2) + 5(3 - x) = 11x - 6
7x - 14 + 15 - 5x = 11x - 6
2x + 1 = 11x - 6
-9x = -7
x = 7/9
5) 4(x + 5) + 3(7 - x) = 49
4x + 20 + 21 - 3x = 49
x + 41 = 49
x = 8
10) 5(3 - x) + 5(x + 4) = 6 + 4x
15 - 5x + 5x + 20 = 6 + 4x
35 = 6 + 4x
4x = 29
x = 29/4
1) 2(x + 5) + 3(x + 7) = 41
2x + 10 + 3x + 21 = 41
5x + 31 = 41
5x = 41 - 31
5x = 10
x = 10 : 5
x = 2
2) 5(x + 6) + 2(x - 3) = 38
5x + 30 + 2x - 6 = 38
7x + 24 = 38
7x = 38 - 24
7x = 14
x = 14 : 7
x = 2
3) 7(5 + x) + 2(x - 10) = 15
35 + 7x + 2x - 20 = 15
9x + 15 = 15
9x = 15 - 15
9x = 0
x = 0
4) 3(x + 4) + (8 - 2x) = 22
3x + 12 + 8 - 2x = 22
x + 20 = 22
x = 22 - 20
x = 2
5) 4(x + 5) + 3(7 - x) = 49
4x + 20 + 21 - 3x = 49
x + 41 = 49
x = 49 - 41
x = 8
6) 7(x - 1) + 5(3 - x) = 11x - 10
7x - 7 + 15 - 5x = 11x - 10
2x - 11x + 8 = -10
-9x = -10 - 8
-9x = -18
x = -18 : (-9)
x = 2
7) 4(2 + x) + 3(x - 2) = 12
8 + 4x + 3x - 6 = 12
7x + 2 = 12
7x = 12 - 2
7x = 10
x = 10/7
8) 5(2 + x) + 4(3 - x) = 10x - 15
10 + 5x + 12 - 4x = 10x - 15
10x - 15 = x + 22
10x - x = 22 + 15
9x = 37
x = 37/9
9) 7(x - 2) + 5(3 - x) = 11x - 6
7x - 14 + 15 - 5x = 11x - 6
11x - 6 = 2x + 1
11x - 2x = 1 + 6
9x = 7
x = 7/9
10) 5(3 - x) + 5(x + 4) = 6 + 4x
15 - 5x + 5x + 20 = 6 + 4x
6 + 4x = 35
4x = 35 - 6
4x = 29
x = 29/4
bài 5 :tìm x, y thuộc Z biết: 1) -x=-7
2) -x=17. 3) |x| =17. 4) -(-x)=|-17| 5) -19-x=17. 6)-19-x=-17. 7) -5-(10-x)=7. 8)|x+3|+7= 12. 9) 2-|x-2| =x. 10)\(^{ }\left(X-2^{ }\right)^2\) = \(^{ }\left(x-2\right)^6\) 11) x.y + x+y =9. 12) 5.xy + x+y =3
( Mik làm mấy phần mà bạn dưới chưa làm)
11) xy+x+y=9
\(\Leftrightarrow\) xy+x+y+1=9+1
\(\Leftrightarrow\left(xy+x\right)+\left(y+1\right)\)=10
\(\Leftrightarrow x\left(y+1\right)+\left(y+1\right)=10\)
\(\Leftrightarrow\) (x+1)(y+1)=10=1.10=10.1=-1.-10=-10.-1=2.5=5.2=-2.-5=-5.-2
\(\Rightarrow\) TH1: x+1=1 ; y+1=10
\(\Leftrightarrow x=0;y=9\)
TH2: x+1=10;y+1=1
\(\Leftrightarrow\)x=9;y=0
TH3: x+1=-1;y+1=-10
\(\Leftrightarrow\) x=-2;y=-11
...........
Vậy:........
( Bạn tự làm nốt chứ dài quá, mik chỉ hướng dẫn cách làm bài thôi)
1) -x = -7
=> x = 7
2) - x = 17
=> x = - 17
3) |x| = 17
=> x = ±17
4) -(-x) = |-17|
=> x = 17
5) - 19 - x = 17
=> - x = 17 + 19
=> x = - 36
6) - 19 - x = - 17
=> - x = - 17 + 19
=> -x = 2
=> x = - 2
7) - 5 - (10 - x) = 7
=> - 5 - 10 + x = 7
=> - 15 + x = 7
=> x = 7 + 15
=> x = 22
8) |x + 3| + 7 = 12
=> |x + 3| = 12 - 7
=> |x + 3| = 5
=> x + 3 = 5 hoặc x + 3 =- 5
=> x = 2 hoặc x = - 8
9) 2 - |x - 2| = x
=> - |x - 2| - x = - 2
TH1: x >= 2
- (x - 2) - x = - 2
=> - x + 2 - x =- 2
=> - 2x = - 4
=> x = 2 (nhận)
TH2: x < 2
-[-(x - 2)] - x = - 2
=> x - 2 - x = - 2
=> 0x = 0 (vô số nghiệm)