Tìm x:
a) X : 4 = 102
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b) X : 7 = 118
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tìm x:
a) 1170 : (x -13) = 339 - 3 . 102
b) (x100)10 . x999 = x
a: =>1170:(x-13)=39
=>x-13=1170/39=30
=>x=43
b: \(\Leftrightarrow x^{1000}\cdot x^{999}-x=0\)
=>\(x\left(x^{1998}-1\right)=0\)
=>\(\left[{}\begin{matrix}x=0\\x^{1998}-1=0\end{matrix}\right.\Leftrightarrow x\in\left\{0;1;-1\right\}\)
Bài 2: Tìm x:
a) 156 – (x+ 61) = 82 b) (x-35) -120 = 0 c) 124 + (118 – x) = 217 d) 7x – 8 = 713 e) x- 36:18 = 12 f) (x- 36):18 = 12 g) (x-47) -115 = 0 |
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Bài 3: Tính nhanh
a) 58.75 + 58.50 – 58.25 b) 27.39 + 27.63 – 2.27 c) 128.46 + 128.32 + 128.22 d) 66.25 + 5.66 + 66.14 + 33.66 e) 12.35 + 35.182 – 35.94 | f) 48.19 + 48.115 + 134.52 g) 27.121 – 87.27 + 73.34 h) 125.98 – 125.46 – 52.25 i) 136.23 + 136.17 – 40.36 j) 17.93 + 116.83 + 17.23 | k) 35.23 + 35.41 + 64.65 l) 29.87 – 29.23 + 64.71 m) 19.27 + 47.81 + 19.20
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Bài 4: Tính giá trị của biểu thức sau:
a) 2763 + 152 b) (-7) + (-14) c) (-35) + (-9) d) (-5) + (-248) e) (-23) + 105 f) 78 + (-123) g) 23 + (-13) h) (-23) + 13 i) 26 + (-6) | j) 80 + (-220) k) (-23) + (-13) l) (-26) + (-6) | m) 12 – 34 n) -23 – 47 o) 31 – (-23) p) -9 – (-5) q) 6 – (8 – 17) r) 19 + (23 – 33) s) (-12 – 44) + (-3) t) 4 – (-15) u) -29 – 23 | v) 99 – [109 + (-9)] w) (-75) + 50 x) (-75) + (-50) y) (-23) + 13 + ( - 17) + 57 z) 14 + 6 + (-9) + (-14)
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a: =>x+61=74
hay x=13
b: =>x-35=120
hay x=155
d: =>7x=721
hay x=103
Tìm x:
a) \(x\) + \(\dfrac{-3}{7}=\dfrac{4}{7}\).
b) \(\dfrac{1}{2}x-75\%=\dfrac{1}{4}.\)
c) \(\left|x-\dfrac{2}{3}\right|+2,25=\dfrac{3}{4}\).
c) Ta có: \(\left|x-\dfrac{2}{3}\right|+2.25=\dfrac{3}{4}\)
\(\Leftrightarrow\left|x-\dfrac{2}{3}\right|=\dfrac{3}{4}-\dfrac{9}{4}=\dfrac{-3}{2}\)(vô lý)
Vậy: \(x\in\varnothing\)
a) Ta có: \(x+\dfrac{-3}{7}=\dfrac{4}{7}\)
\(\Leftrightarrow x-\dfrac{3}{7}=\dfrac{4}{7}\)
hay x=1
Vậy: x=1
b) Ta có: \(\dfrac{1}{2}x-75\%=\dfrac{1}{4}\)
\(\Leftrightarrow x\cdot\dfrac{1}{2}=1\)
hay x=2
Vậy: x=2
Tìm x:
a, \(x-\dfrac{1}{4}=\dfrac{7}{2}.\dfrac{-3}{5}\)
b, \(\dfrac{x}{134}=\dfrac{9}{7}.\dfrac{5}{-11}\)
\(a,x-\dfrac{1}{4}=\dfrac{7}{2}.\dfrac{-3}{5}\\ \Rightarrow x-\dfrac{1}{4}=\dfrac{-21}{10}\\ \Rightarrow x=\dfrac{-21}{10}+\dfrac{1}{4}\\ \Rightarrow x=\dfrac{-37}{20}\\ b,\dfrac{x}{134}=\dfrac{9}{7}.\dfrac{5}{-11}\\ \Rightarrow\dfrac{x}{134}=\dfrac{-45}{77}\\ \Rightarrow x=\dfrac{-45}{77}.134\\ \Rightarrow x=\dfrac{-6030}{77}\)
\(x-\dfrac{1}{4}=\dfrac{7}{2}\cdot\dfrac{-3}{5}\)
\(x-\dfrac{1}{4}=\dfrac{-21}{10}\)
\(x=\dfrac{-21}{10}+\dfrac{1}{4}\)
\(x=\dfrac{-37}{20}\)
b ) \(\dfrac{x}{134}=\dfrac{9}{7}\cdot\dfrac{5}{-11}\)
\(\dfrac{x}{134}=\dfrac{9}{7}\cdot\dfrac{-5}{11}\)
\(\dfrac{x}{134}=\dfrac{-45}{77}\)
\(x=\dfrac{-45}{77}\cdot134\)
\(x=-\dfrac{6034}{77}\)
Tìm x:
a) (x + 5)2 - x(x - 4) = 55
b) x(x - 7) - 3x + 21 = 0
a: \(\Leftrightarrow x^2+10x+25-x^2+4x=55\)
=>14x=30
hay x=15/7
b: \(\Leftrightarrow\left(x-7\right)\left(x-3\right)=0\)
hay \(x\in\left\{7;3\right\}\)
Tìm x:
a) x+ 1/5-2,7=5 1/2 b)2 3/4 +x-7/8=6
Mọi người giúp em với
a: =>x+1/5-27/10=11/2
=>x-5/2=11/2
hay x=8
b: =>11/4+x-7/8=6
=>15/8+x=6
hay x=33/8
Mọi người giúp em với
Em đang cần gấpTìm x:
a) x - 1\(\dfrac{3}{5}\)= 2\(\dfrac{1}{10}\) b) \(5\dfrac{1}{7}\) : x = \(4\dfrac{1}{2}\)
\(a,x-1\dfrac{3}{5}=2\dfrac{1}{10}\\ x-\dfrac{8}{5}=\dfrac{21}{10}\\ x=\dfrac{21}{10}+\dfrac{8}{5}\\ x=\dfrac{21}{10}+\dfrac{16}{10}\\ x=\dfrac{37}{10}\\ b,5\dfrac{1}{7}:x=4\dfrac{1}{2}\\ \dfrac{36}{7}:x=\dfrac{9}{2}\\ x=\dfrac{36}{7}:\dfrac{9}{2}\\ x=\dfrac{36}{7}\cdot\dfrac{2}{9}\\ x=\dfrac{8}{7}\)
Tìm x:
a) x - \(\dfrac{5}{7}\) = \(\dfrac{3}{5}\) x \(\dfrac{1}{2}\) b) x \(x\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{3}{4}\)
\(a,x-\dfrac{5}{7}=\dfrac{3}{5}\times\dfrac{1}{2}\)
\(x-\dfrac{5}{7}=\dfrac{3}{10}\)
\(x=\dfrac{3}{10}+\dfrac{5}{7}\)
\(x=\dfrac{21}{70}+\dfrac{50}{70}\)
\(x=\dfrac{71}{70}\)
\(Vayx=\dfrac{71}{70}\)
\(b,x\times\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{3}{4}\)
\(x\times\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{6}{8}\)
\(x\times\dfrac{2}{3}=\dfrac{11}{8}\)
\(x=\dfrac{11}{8}:\dfrac{2}{3}\)
\(x=\dfrac{11}{8}\times\dfrac{3}{2}\)
\(x=\dfrac{33}{16}\)
\(Vayx=\dfrac{33}{16}\)
Bài4:Tìm x:
a. 124 + (118 – x) = 217 b. 7x – 8 = 713 c. x- 36:18 = 12 d. (x- 36):18 = 12 e. (x-47) -115 = 0 f. 315 + (146 – x) = 401 | g. (6x – 39 ) : 3 = 201 h. 23 + 3x = 56 : 53 i. 5x + x = 39 – 311:39 j. 7x – x = 521 : 519 + 3.22 - 70 k. 7x – 2x = 617: 615 + 44 : 11 l. 0 : x = 0 | m. 3x = 9 n. 4x = 64 o. 2x = 16 p. 9x- 1 = 9 q. x4 = 16 r. 2x : 25 = 1 |
Bài4:Tínhnhanh
1. 58.75 + 58.50 – 58.25 2. 27.39 + 27.63 – 2.27 3. 128.46 + 128.32 + 128.22 4. 87.23 + 13.93 + 70.87
| 5. 12.35 + 35.182 – 35.94 6. 48.19 + 48.115 + 134.52 7. 27.121 – 87.27 + 73.34 8. 136.23 + 136.17 – 40.36 9. 125.98 – 125.46 – 52.25 | 10. 17.93 + 116.83 + 17.233 11. 5.23 + 35.41 + 64.65 12. 29.87 – 29.23 + 64.71 13. 19.27 + 47.81 + 19.20
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b: Ta có: 7x-8=713
nên 7x=721
hay x=103
c: Ta có: x-36:18=12
nên x-2=12
hay x=14
d: Ta có: (x-36):18=12
nên x-36=216
hay x=252
a. 124 + (118 – x) = 217
118 - x = 93
- x = - 25
x = 25
b. 7x – 8 = 713
7x =721
x =103
c. x- 36:18 = 12
x- 2 =12
x =14
d. (x- 36):18 = 12
x-36 = 216
x = 252
e. (x-47) -115 = 0
x-47 = 115
x = 162
f. 315 + (146 – x) = 401
146-x =86
-x = -60
x = 60
g. (6x – 39 ) : 3 = 201
6x - 39 = 603
6x = 642
x = 107
h. 23 + 3x = 56 : 53
23 +3x = 125
3x = 102
x=34