Bai 1 tim x
2/3 x -3/2 x=5/12
72-3/x+1/=9
7/9 : (2+3/4 x)+5/9=23/27
bai 1 : tinh nhanh :
a) -3/7+ 15/26 - (2/13 - 3/7 ) b) 2.3/7+(2/9-1\(\frac{3}{7}\)) - 5/3 : 1/9 c) -11/23 . 6/7 + 8/7 .-11/23 - 1/23 d) ( 377/231 - 123/89 + 34 /701 ) . ( 1/6 - 1/8 -1 /24)
bai 2 . tim so x biet :
a ) 2/3x - 3/2x = 5/12 b) 2/5 + 3/5 . ( 3x-3,7) = -53/10 c) 7/9:(2+3/4x)+5/9=23/27 d,-2/3.x +1/5=3/10 e, /x/-3/4=5/3
f, /2x-1/3/+5/6=1
Tim X
3) -12 + (2x – 9) + x= 0
4) 11 + (15 - x) = 1
5) 4 - (27 - 3) = x - (13 - 4)
6) 8 - (x - 10) = 23 - (- 4 +12)
7) 105 – 5(10 – 5x) = -20
8) (x -1)(8-2x)(3x+123) = 0
9) (x2 - 25)(x+ 10) = 0
10) x(x2+5) =
3) \(-12+2x-9+x=0\\ -21+3x=0\\ 3x=21\\ x=7\)
4)
\(11+\left(15-x\right)=1\)
\(15-x=1-11\)
\(15-x=-10\)
\(x=15-\left(-10\right)\)
\(x=25\)
5)
\(4-\left(27-3\right)=x-\left(13-4\right)\)
\(4-24=x-9\)
\(x-9=-20\)
\(x=-20+9\)
\(x=-11\)
\(3.-12+\left(2x-9\right)+x=0.\)
\(\Leftrightarrow-12+2x-9+x=0.\Leftrightarrow3x=21.\Leftrightarrow x=7.\)
Vậy \(x=7.\)
\(4.11+\left(15-x\right)=1.\Leftrightarrow11+15-x=1.\Leftrightarrow26-x=1.\Leftrightarrow x=25.\)
Vậy \(x=25.\)
\(5.4-\left(27-3\right)=x-\left(13-4\right).\Leftrightarrow4-24=x-9.\Leftrightarrow-20=x-9.\Leftrightarrow x=-11.\)
Vậy \(x=-11.\)
\(6.8-\left(x-10\right)=23-\left(-4+12\right).\Leftrightarrow8-x+10=23-8.\Leftrightarrow18-x=15.\Leftrightarrow x=3.\)
Vậy \(x=3.\)
\(7.105-5\left(10-5x\right)=-20.\Leftrightarrow105-50+25x=-20.\Leftrightarrow25x=-75.\Leftrightarrow x=-3.\)
Vậy \(x=-3.\)
\(8.\left(x-1\right)\left(8-2x\right)\left(3x+123\right)=0.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0.\\8-2x=0.\\3x+123=0.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1.\\x=4.\\x=-41.\end{matrix}\right.\)
Vậy \(x\in\left\{1;4;-41\right\}.\)
\(9.\left(x^2-25\right)\left(x+10\right)=0.\)
\(\Leftrightarrow\left(x-5\right)\left(x+5\right)\left(x+10\right)=0.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-5=0.\\x+5=0.\\x+10=0.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5.\\x=-5.\\x=-10.\end{matrix}\right.\)
Vậy \(x\in\left\{5;-5;-10\right\}.\)
\(10.x\left(x^2+5\right)=0.\Leftrightarrow x=0.\)
Bài 1:
1)-7/9x2 3/4
2)2/3+1/3x-2/5
3) 3/4 x 15 1/3 - 3/4 x 43 1/3
4) (-49,1)x 13/27 - 58,9 x 13/27
5) 0,375 : (-4,5)
6) 3 1/7 :( -1 3/7)
7) 9 1/3 :4 2/3 - 2
8) ( 7 3/4 : 0,3125 + 4,5 x2 2/45) : (-8,5)
Bài 2
A= (-6/11) x 7/10 x (11/-6) x(-20)
B= (-1/9) x (-17/29) x 58/51
C=(-3/7) x 5/11 +(-5/14)x5/11
D=(1 1/27 x 12/23 x 9/14 ) :(-3/23)
Bài 3 tìm x
a) 3/7x -2/5 x+-17/33
b)(3/4 x - 9/16).(1/3 +-3/5 : x)=0
c)(x+3/5 ) . (x+1)<0
(Hạn thứ 3 nha , giúp mk vs)
1) 27,56 x 35 + 27,56 x67- 27,56 x2
2) 4 x 35 x 25 x 5 x2
3) ( 32 x 18 - 16 x 36 ) x( 1+3+5+7+......+1001)
4) 3/5 + 2/5 x 1/2 - 2/3 x 3/4
5) 27 x 13 + 35 x 27 - 12 x 9
6) 33/5 x 15/11 + 22/27 x 81/44 - 3/5 : 9/5
1).( 27,56 x 35 ) + ( 27,56 x 67 ) - ( 27,56 x 2)
= (964 + 1846,52) - 55,12
=2810,52 - 55,12
= 2755,4
2).( 4x 35 ) x ( 25 x 5 ) x 2
= ( 140 x 125 ) x2
= 17500 x 2
=35000
4). 3/10
5). 1188
6). 61/6
1,2755,4
2,35000
3,0
4,\(\frac{3}{10}\)
5,1188
6,\(\frac{61}{6}\)
tim x
2/5+2/5.(3.x-3,7)=-53/10
7/9 / (2+3/4.x)+5/9=23/27
Mấy bài này bình thường mà bạn ! Bạn áp dụng tính chất phân phối
Tính nhanh: LƯU Ý tất cả số dưới đây đều là phân số
1,1/8 x 2/5 + 3/5 + 1/8
2,( -1)/15 x 2/5 + (-5)/3 x (-1)/13
3,4/9 : 11/6 + 5/9 x 6/11
4,5/19 x 7/13 + 7/19 x 8/13 - 3 x 7/19
5, 2/7 x 4/23 - 2/7 x 27/23 + 2/7
6,3/8 x 3/7 +3/8 x 4/7 + 11/8
7,-5/27 : 6/11 - 16/11 x 5/27 - 5/27
8, 5/16 x 7/8 - 5/16 x 1/8 + 10/8 :16/5
9,1/3 x 39/17 - 129/3 x 1/17
10,5/2 : 23/3 - 3/2 x 7/23
2: \(=\dfrac{-2}{75}+\dfrac{5}{39}=\dfrac{33}{325}\)
3: \(=\dfrac{6}{11}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{6}{11}\)
4: \(=\dfrac{7}{19}\left(\dfrac{5}{13}+\dfrac{8}{13}-1\right)=-2\cdot\dfrac{7}{19}=-\dfrac{14}{19}\)
5: \(=\dfrac{2}{7}\left(\dfrac{4}{23}-\dfrac{27}{23}+1\right)=0\)
6: \(=\dfrac{3}{8}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)+\dfrac{11}{8}=\dfrac{3}{8}+\dfrac{11}{8}=\dfrac{14}{8}=\dfrac{7}{4}\)
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
-->\(\orbr{\begin{cases}2x-\frac{1}{3}=\frac{1}{6}\\2x-\frac{1}{3}=-\frac{1}{6}\end{cases}}\)
-->\(\orbr{\begin{cases}2x=\frac{1}{6}+\frac{1}{3}\\2x=-\frac{1}{6}+\frac{1}{3}\end{cases}}\)
-->\(\orbr{\begin{cases}2x=\frac{1}{2}\\2x=\frac{1}{6}\end{cases}}\)
-->\(\orbr{\begin{cases}x=\frac{1}{2}:2\\x=\frac{1}{6}:2\end{cases}}\)
-->\(\orbr{\begin{cases}x=\frac{1}{4}\\x=\frac{1}{12}\end{cases}}\)
1. (x-6)^2 = 2(x-6)
2. 2(x-3)^2 = (x-3)(x+5)
3. 4(x-3)=2x-5(2x+3)
4. x2 +4 -2 (x-1) = (x-2)^2
5. x-3/5 = 6 - 1-2x/3
6. x+2 = 6-5x/2
7. x+2/5 - x+3 = x-2/2
8. 2x-5/x-4 = 2x+1/x+2
9. X+3/x-3 - x-1/x+3 = x2 + 4x + 6/x2 -9
10. 3x-3/x2-9 -1/x-3 = x+1/x+3
11. X+1/x-1 - x-1/x+1 = 4/x2 -1
Bài dài quá, lần sau chia nhỏ câu hỏi nhé!!!!!
Tim x biet
c) \(\frac{7}{9}:\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)
d) \(|x-\frac{1}{3}|-\frac{3}{4}=\frac{5}{3}\)
c) \(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)
\(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)=\frac{23}{27}-\frac{5}{9}\)
\(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)=\frac{23}{27}-\frac{15}{27}\)
\(\frac{7}{9}\div\left(2+\frac{3}{4}x\right)=\frac{8}{27}\)
\(2+\frac{3}{4}x=\frac{7}{9}\div\frac{8}{27}\)
\(2+\frac{3}{4}x=\frac{7}{9}.\frac{27}{8}\)
\(2+\frac{3}{4}x=\frac{21}{8}\)
\(\frac{3}{4}x=\frac{21}{8}-2\)
\(\frac{3}{4}x=\frac{21}{8}-\frac{16}{8}\)
\(\frac{3}{4}x=\frac{5}{8}\)
\(x=\frac{5}{8}\div\frac{3}{4}\)
\(x=\frac{5}{8}.\frac{4}{3}\)
\(x=\frac{5}{6}\)
Vậy \(x=\frac{5}{6}\).
d) \(\left|x-\frac{1}{3}\right|-\frac{3}{4}=\frac{5}{3}\)
\(\left|x-\frac{1}{3}\right|=\frac{5}{3}+\frac{3}{4}\)
\(\left|x-\frac{1}{3}\right|=\frac{20}{12}+\frac{9}{12}\)
\(\left|x-\frac{1}{3}\right|=\frac{29}{12}\)
\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{3}=\frac{29}{12}\\x-\frac{1}{3}=-\frac{29}{12}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{11}{4}\\x=-\frac{25}{12}\end{cases}}\)
Vậy \(x\in\left\{\frac{11}{4};-\frac{25}{12}\right\}\).