a) 3.x -2=7
b) 5.x+4=(-3)+17
C) 22-2.x =4¹́5:4¹³
a. 2/3x-1/2=1/10
b. 39/7:x=13
c. (14/5x-50):2/3=51
d. (x+1/2)(2/3-2x)=0
e. 2/3x-1/2x=5/12
g. (x.44/7+3/7)11/5-3/7=-2
h. x.13/4+(-7/6)x-5/3=5/12
i.93/17:x+(-4/17):x+22/7:52/3=4/11
j. 17/2-|2x-3/4|=-7/4
k. (x+1/5)^2+17/25=26/25
l. -32/27-(3x-7/9)^3=-24/27
a) \(\dfrac{2}{3}x-\dfrac{1}{2}=\dfrac{1}{10}\)
\(\dfrac{2}{3}x=\dfrac{1}{10}+\dfrac{1}{2}=\dfrac{3}{5}\)
\(x=\dfrac{3}{5}:\dfrac{2}{3}=\dfrac{9}{10}\)
b) \(\dfrac{39}{7}:x=13\)
\(x=\dfrac{\dfrac{39}{7}}{13}=\dfrac{3}{7}\)
c) \(\left(\dfrac{14}{5}x-50\right):\dfrac{2}{3}=51\)
\(\dfrac{14}{5}x-50=51\cdot\dfrac{2}{3}=34\)
\(\dfrac{14}{5}x=34+50=84\)
\(x=\dfrac{84}{\dfrac{14}{5}}=30\)
d) \(\left(x+\dfrac{1}{2}\right)\left(\dfrac{2}{3}-2x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{2}=0\\\dfrac{2}{3}-2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)
e) \(\dfrac{2}{3}x-\dfrac{1}{2}x=\dfrac{5}{12}\)
\(\dfrac{1}{6}x=\dfrac{5}{12}\)
\(x=\dfrac{5}{12}:\dfrac{1}{6}=\dfrac{5}{2}\)
g) \(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\dfrac{11}{5}-\dfrac{3}{7}=-2\)
\(\left(x\cdot\dfrac{44}{7}+\dfrac{3}{7}\right)\cdot\dfrac{11}{5}=-2+\dfrac{3}{7}=-\dfrac{11}{7}\)
\(x\cdot\dfrac{44}{7}+\dfrac{3}{7}=-\dfrac{11}{7}:\dfrac{11}{5}=-\dfrac{5}{7}\)
\(\dfrac{44}{7}x=-\dfrac{5}{7}-\dfrac{3}{7}=-\dfrac{8}{7}\)
\(x=-\dfrac{8}{7}:\dfrac{44}{7}=-\dfrac{2}{11}\)
h) \(\dfrac{13}{4}x+\left(-\dfrac{7}{6}\right)x-\dfrac{5}{3}=\dfrac{5}{12}\)
\(\dfrac{25}{12}x-\dfrac{5}{3}=\dfrac{5}{12}\)
\(\dfrac{25}{12}x=\dfrac{5}{12}+\dfrac{5}{3}=\dfrac{25}{12}\)
\(x=1\)
Mỏi tay woa bn làm nốt nha!!
Tính bằng cách thuận tiên nhất:
1):(3/4 x 5/97 + 1/9 x 13/47) x (1/5 - 7/25 x 5/7)
2): 8/17 x 4/15 + 8/17 x 22/15 - 8/15 x 9/17
3): 2021/2 x 1/3 + 4042/4 x 1/5 + 6063/3 x 22/15
4); 4/7 x 2/13 + 8/13 :7/4 + 4/7 : 13/2 + 4/7 x 1/13
5): 2022 x 2021 - 1/ 2021 + 2022 x 2020
6): 18 x 123 + 9 x 4567 x 2 + 3 x 5310 x 6 / (2 + 4 + 6 + 8 + ...+20 + 22) + 48
7): A= 2021 x 2021 x 202020 - 2020 x 2020 x 20212021 / 2020 x 20192019
1) Ta có: \(\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{7}{25}\cdot\dfrac{5}{7}\right)\)
\(=\left(\dfrac{3}{4}\cdot\dfrac{5}{97}+\dfrac{1}{9}\cdot\dfrac{13}{47}\right)\cdot\left(\dfrac{1}{5}-\dfrac{1}{5}\right)\)
=0
2) Ta có: \(\dfrac{8}{17}\cdot\dfrac{4}{15}+\dfrac{8}{17}\cdot\dfrac{22}{15}-\dfrac{8}{15}\cdot\dfrac{9}{17}\)
\(=\dfrac{8}{17}\left(\dfrac{4}{15}+\dfrac{22}{15}-\dfrac{9}{15}\right)\)
\(=\dfrac{8}{17}\cdot\dfrac{15}{15}=\dfrac{8}{17}\)
3) Ta có: \(\dfrac{2021}{2}\cdot\dfrac{1}{3}+\dfrac{4042}{4}\cdot\dfrac{1}{5}+\dfrac{6063}{3}\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)+2021\cdot\dfrac{22}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{8}{15}+\dfrac{2021}{2}\cdot\dfrac{44}{15}\)
\(=\dfrac{2021}{2}\cdot\dfrac{52}{15}\)
\(=\dfrac{52546}{15}\)
4) Ta có: \(\dfrac{4}{7}\cdot\dfrac{2}{13}+\dfrac{8}{13}:\dfrac{7}{4}+\dfrac{4}{7}:\dfrac{13}{2}+\dfrac{4}{7}\cdot\dfrac{1}{13}\)
\(=\dfrac{4}{7}\left(\dfrac{2}{13}+\dfrac{8}{13}+\dfrac{2}{13}+\dfrac{1}{13}\right)\)
\(=\dfrac{4}{7}\)
Tìm x biet:
a,93/17:x+(-21/17):x+22/7:22/3=5/14
b,-32/27-(3x-7/9)^3=-24/27
c,[(3,75:1/4)+12/5.125%)-(7/2.0,8-1,2:3/2)]:(3/2+0,75)x=64
a; \(\dfrac{93}{17}\): \(x\) + (- \(\dfrac{21}{17}\)) : \(x\) + \(\dfrac{22}{7}\): \(\dfrac{22}{3}\) = \(\dfrac{5}{14}\)
\(\dfrac{94}{17}\) \(\times\) \(\dfrac{1}{x}\) - \(\dfrac{21}{17}\) \(\times\) \(\dfrac{1}{x}\) + \(\dfrac{3}{7}\) = \(\dfrac{5}{14}\)
\(\dfrac{72}{17}\) \(\times\) \(\dfrac{1}{x}\) + \(\dfrac{3}{7}\) = \(\dfrac{5}{14}\)
\(\dfrac{72}{17x}\) = \(\dfrac{5}{14}\) - \(\dfrac{3}{7}\)
\(\dfrac{72}{17x}\) = - \(\dfrac{1}{14}\)
17\(x\) = 72.(-14)
17\(x\) = - 1008
\(x\) = - 1008 : 17
\(x\) = - \(\dfrac{1008}{17}\)
Vậy \(x\) \(=-\dfrac{1008}{17}\)
b; - \(\dfrac{32}{27}\) - (3\(x\) - \(\dfrac{7}{9}\))3 = - \(\dfrac{24}{27}\)
- \(\dfrac{32}{27}\) + \(\dfrac{24}{27}\) = (3\(x\) - \(\dfrac{7}{9}\))3
(3\(x-\dfrac{7}{9}\))3 = - \(\dfrac{8}{27}\)
(3\(x-\dfrac{7}{9}\))3 = (- \(\dfrac{2}{3}\))3
3\(x-\dfrac{7}{9}\) = - \(\dfrac{2}{3}\)
3\(x\) = - \(\dfrac{2}{3}\) + \(\dfrac{7}{9}\)
3\(x\) = \(\dfrac{1}{9}\)
\(x\) = \(\dfrac{1}{9}\) : 3
\(x\) = \(\dfrac{1}{27}\)
Vậy \(x=\dfrac{1}{27}\)
Tìm x : |x|-38/7*|x|-3/4=2|x|+(-8/7)
x*13/4+(-7/6)*x-5/3=5/12
93/17:x+(-4/17):x+22/7:52/3=4/11
a: \(\left|x\right|-\dfrac{38}{7}\left|x\right|-\dfrac{3}{4}=2\left|x\right|-\dfrac{8}{7}\)
\(\Leftrightarrow\left|x\right|\cdot\dfrac{-45}{7}=-\dfrac{8}{7}+\dfrac{3}{4}=\dfrac{-32+21}{28}=\dfrac{-11}{28}\)
=>|x|=11/180
=>x=11/180 hoặc x=-11/180
b: \(\Leftrightarrow x\cdot\dfrac{13}{4}-\dfrac{7}{6}x=\dfrac{5}{12}+\dfrac{5}{3}\)
=>25/12x=25/12
hay x=1
tìm x biết
a ) x/5 - 7/3 + 3/4 = 17/60
b ) 1/8 - 7/5 - 2/x = (-233)/120
c ) 1/5 + x - 7/3 = 1/2
d ) (-1)/3 - x - 4/5 = 4/15
e ) x : 17/8 = (-2)/5 . (-9)/17
f ) x : 4 = (-5)/2
g ) 5/7: x + 2/5 = 1/5
i ) -12/7 . ( 3/4 - x ) . 5/3 = 0
đâu / có nghĩa là dấu phân số nha
ai nhanh mk tick nha !
a,4x-10=0 b, 7-3x=9-x c, 2x-(3-5x) = 4(x+3)
d, 5-(6-x)=4(3-2x) e, 4(x+3)=-7x+17 f, 5(x-3) - 4=2(x-1)+7
g, 5(x-3)-4=2(x-1)+7 h,4(3x-2)-3(x-4)=7x+20
`a,4x-10=0 `
`<=> 4x=10`
`<=>x=10/4`
`<=>x=5/2`
`b, 7-3x=9-x `
`<=>-3x+x=9-7`
`<=>-2x=2`
`<=>x=-1`
`c, 2x-(3-5x) = 4(x+3)`
`<=>2x-3+5x=4x+12`
`<=>2x+5x-4x=12+3`
`<=>3x=15`
`<=>x=5`
`d, 5-(6-x)=4(3-2x) `
`<=>5-6+x=12-8x`
`<=>x+8x=12-5+6`
`<=>9x=13`
`<=>x=13/9`
`e, 4(x+3)=-7x+17 `
`<=>4x+12=-7x+17`
`<=>4x+7x=17-12`
`<=>11x=5`
`<=>x=5/11`
`f, 5(x-3) - 4=2(x-1)+7`
`<=>5x-15-4=2x-2+7`
`<=>5x-2x=15+4-2+7`
`<=>3x=24`
`<=>x=8`
`g, 5(x-3)-4=2(x-1)+7 `
`<=>5x-15-4=2x-2+7`
`<=>5x-2x=15+4-2+7`
`<=>3x=24`
`<=>x=8`
`h,4(3x-2)-3(x-4)=7x+20`
`<=>12x-8-3x+12=7x+20`
`<=>12x-3x-7x=20+8+12`
`<=>2x=40`
`<=>x=20`
Bài 1: Tính hợp lí
1/ (-37) + 14 + 26 + 37
2/ (-24) + 6 + 10 + 24
3/ 15 + 23 + (-25) + (-23)
4/ 60 + 33 + (-50) + (-33)
5/ (-16) + (-209) + (-14) + 209
6/ (-12) + (-13) + 36 + (-11)
7/ -16 + 24 + 16 – 34
8/ 25 + 37 – 48 – 25 – 37
9/ 2575 + 37 – 2576 – 29
10/ 34 + 35 + 36 + 37 – 14 – 15 – 16 – 17
Bài 2: Bỏ ngoặc rồi tính
1/ -7264 + (1543 + 7264)
2/ (144 – 97) – 144
3/ (-145) – (18 – 145)
4/ 111 + (-11 + 27)
5/ (27 + 514) – (486 – 73)
6/ (36 + 79) + (145 – 79 – 36)
7/ 10 – [12 – (- 9 - 1)]
8/ (38 – 29 + 43) – (43 + 38)
9/ 271 – [(-43) + 271 – (-17)]
10/ -144 – [29 – (+144) – (+144)]
Bài 3: Tính tổng các số nguyên x biết:
1/ -20 < x < 21
2/ -18 ≤ x ≤ 17
3/ -27 < x ≤ 27
4/ │x│≤ 3
5/ │-x│< 5
Bài 4: Tính tổng
1/ 1 + (-2) + 3 + (-4) + . . . + 19 + (-20)
2/ 1 – 2 + 3 – 4 + . . . + 99 – 100
3/ 2 – 4 + 6 – 8 + . . . + 48 – 50
4/ – 1 + 3 – 5 + 7 - . . . . + 97 – 99
5/ 1 + 2 – 3 – 4 + . . . . + 97 + 98 – 99 - 100
Bài 5: Tính giá trị của biểu thức
1/ x + 8 – x – 22 với x = 2010
2/ - x – a + 12 + a với x = - 98 ; a = 99
3/ a – m + 7 – 8 + m với a = 1 ; m = - 123
4/ m – 24 – x + 24 + x với x = 37 ; m = 72
5/ (-90) – (y + 10) + 100 với p = -24
Bài 6: Tìm x
1/ -16 + 23 + x = - 16
2/ 2x – 35 = 15
3/ 3x + 17 = 12
4/ │x - 1│= 0
5/ -13 .│x│ = -26
Bài 7: Tính hợp lí
1/ 35. 18 – 5. 7. 28
2/ 45 – 5. (12 + 9)
3/ 24. (16 – 5) – 16. (24 - 5)
4/ 29. (19 – 13) – 19. (29 – 13)
5/ 31. (-18) + 31. ( - 81) – 31
6/ (-12).47 + (-12). 52 + (-12)
7/ 13.(23 + 22) – 3.(17 + 28)
8/ -48 + 48. (-78) + 48.(-21)
Bài 8: Tính
1/ (-6 – 2). (-6 + 2)
2/ (7. 3 – 3) : (-6)
3/ (-5 + 9) . (-4)
4/ 72 : (-6. 2 + 4)
5/ -3. 7 – 4. (-5) + 1
6/ 18 – 10 : (+2) – 7
7/ 15 : (-5).(-3) – 8
8/ (6. 8 – 10 : 5) + 3. (-7)
Bài 9: So sánh
1/ (-99). 98 . (-97) với 0
2/ (-5)(-4)(-3)(-2)(-1) với 0
3/ (-245)(-47)(-199) với
123.(+315)
4/ 2987. (-1974). (+243). 0 với 0
5/ (-12).(-45) : (-27) với │-1│
Bài 13: Tìm x:
1/ (2x – 5) + 17 = 6
Bài 14: Tìm x
1/ x.(x + 7) = 0
2/ 10 – 2(4 – 3x) = -4
3/ - 12 + 3(-x + 7) = -18
4/ 24 : (3x – 2) = -3
5/ -45 : 5.(-3 – 2x) = 3
2/ (x + 12).(x-3) = 0
3/ (-x + 5).(3 – x ) = 0
4/ x.(2 + x).( 7 – x) = 0
5/ (x - 1).(x +2).(-x -3) = 0
Bài 15: Tìm
1/ Ư(10) và B(10)
2/ Ư(+15) và B(+15)
3/ Ư(-24) và B(-24)
4/ ƯC(12; 18)
5/ ƯC(-15; +20)
Bài 16: Tìm x biết
1/ 8 x và x > 0
2/ 12 x và x < 0
3/ -8 x và 12 x
4/ x 4 ; x (-6) và -20 < x < -10
5/ x (-9) ; x (+12) và 20 < x < 50
Bài 17: Viết dười dạng tích các tổng sau:
1/ ab + ac
2/ ab – ac + ad
3/ ax – bx – cx + dx
4/ a(b + c) – d(b + c)
5/ ac – ad + bc – bd
6/ ax + by + bx + ay
Bài 18: Chứng tỏ
1/ (a – b + c) – (a + c) = -b
2/ (a + b) – (b – a) + c = 2a + c
3/ - (a + b – c) + (a – b – c) = -2b
4/ a(b + c) – a(b + d) = a(c – d)
5/ a(b – c) + a(d + c) = a(b + d)
Bài 19: Tìm a biết
1/ a + b – c = 18 với b = 10 ; c = -9
2/ 2a – 3b + c = 0 với b = -2 ; c = 4
3/ 3a – b – 2c = 2 với b = 6 ; c = -1
4/ 12 – a + b + 5c = -1 với b = -7 ; c = 5
5/ 1 – 2b + c – 3a = -9 với b = -3 ; c = -7
Bài 20: Sắp xếp theo thứ tự
* tăng dần
1/ 7; -12 ; +4 ; 0 ; │-8│; -10; -1
2/ -12; │+4│; -5 ; -3 ; +3 ; 0 ; │-5│
* giảm dần
3/ +9 ; -4 ; │-6│; 0 ; -│-5│; -(-12)
4/ -(-3) ; -(+2) ; │-1│; 0 ; +(-5) ; 4 ; │+7│; -8
mình giải từng bài nhá
hả đơn giản
bài 1 : tính
a) 1/7 : 5/17 - 3/2 . ( 1/6 - 7/12 )
b) 25/77 - ( 1/5 - 7/15 ) : 10/11 : |-3/4|
c) 4/7 + 15/4 - 11/4 + 3/7 - 1/2 + 1/3
bài 2 : tìm x
a) 3/4.x + 1/2 = -3/5
b) x-5/4 = 1/3 - 3/4 .x
c) -2/3 . ( x - 1/4 ) = 1/3 . ( 2x-1)
Bài 2:
a: =>3/4x=-3/5-1/2=-11/10
\(\Leftrightarrow x=\dfrac{-11}{10}:\dfrac{3}{4}=\dfrac{-11}{10}\cdot\dfrac{4}{3}=-\dfrac{44}{30}=-\dfrac{22}{15}\)
b: \(\Leftrightarrow x+\dfrac{3}{4}x=\dfrac{1}{3}+\dfrac{5}{4}=\dfrac{19}{12}\)
=>7/4x=19/12
=>x=19/21
c: \(\Leftrightarrow-\dfrac{2}{3}x+\dfrac{1}{6}=\dfrac{2}{3}x-\dfrac{1}{3}\)
=>-4/3x=-1/3-1/6=-1/2
=>x=1/2:4/3=1/2x3/4=3/8
Bài 1
\(\dfrac{1}{7}:\dfrac{5}{17}-\dfrac{3}{2}.\left(\dfrac{1}{6}-\dfrac{7}{12}\right)\)
\(\dfrac{1}{7}.\dfrac{17}{5}-\dfrac{3}{2}.\left(-\dfrac{5}{12}\right)\)
\(\dfrac{17}{35}-\left(-\dfrac{5}{8}\right)\)
\(\dfrac{17}{35}+\dfrac{5}{8}\)
\(\dfrac{311}{280}\)
Bài 1: thực hiện phép tính
a, (3/8 + -3/4 + 7/12) : 5/6 + 1/2
b, -7/3. 5/9+ 4/9. (-3/7)+ 17/7
c,117/13 - (2/5 + 57/13)
d, 2/3 - 0,25 : 3/4 + 5/8 .4
Bài 2: tìm x biết
a, 2/3 x - 1/2 = 1/10
b, -2/3 -1/3 (2x -5) = 3/2
c, (3x -1) (-1/2 x + 7) =0
d, 17/2 - | 2x - 3/4 | =-7/4
e, (x + 1/25) +17/25 = 26/25
\(a,\left(\frac{3}{8}+-\frac{3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
= \(\left(-\frac{3}{8}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
= \(\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)
= \(\frac{1}{4}+\frac{1}{2}\)
= \(\frac{3}{4}\)
b)\(-\frac{7}{3}.\frac{5}{9}+\frac{4}{9}.\left(-\frac{3}{7}\right)+\frac{17}{7}\)
=\(-\frac{35}{27}+\left(-\frac{4}{21}\right)+\frac{17}{7}\)
= \(-\frac{35}{27}+\frac{47}{21}\)
= \(\frac{178}{189}\)
c) \(\frac{117}{13}-\left(\frac{2}{5}+\frac{57}{13}\right)\)
= \(\frac{117}{13}-\frac{311}{65}\)
= \(\frac{274}{65}\)
d) \(\frac{2}{3}-0,25:\frac{3}{4}+\frac{5}{8}.4\)
= \(\frac{2}{3}-\frac{1}{4}:\frac{3}{4}+\frac{5}{8}.4\)
= \(\frac{2}{3}-\frac{1}{3}+\frac{5}{2}\)
= \(\frac{1}{3}+\frac{5}{2}\)
= \(\frac{17}{6}\)