T
3
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
NT
2
f) (x – 5)2 = 9
TG
9 tháng 2 2021
a) 3x – 15 = 25 – 5x
=> 3x + 5x = 25 + 15
=> 8x = 40
=> x = 5
b) 3x - 17 = 2x – 7
=> 3x - 2x = -7 + 17
=> x = 10
c) 2x – 17 = – (3x – 18)
=> 2x - 17 = -3x + 18
=> 2x + 3x = 18 + 17
=> 5x = 35
=> x = 7
d) 3x – 14 = 2(x – 9) + 1
=> 3x - 14 = 2x - 18 + 1
=> 3x - 2x = -18 + 1 + 14
=> x = -3
f) (x – 5)2 = 9
\(\Rightarrow\left[{}\begin{matrix}x-5=3\\x-5=-3\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=8\\x=2\end{matrix}\right.\)
9 tháng 2 2021
a) Ta có: \(3x-15=25-5x\)
\(\Leftrightarrow3x-15-25+5x=0\)
\(\Leftrightarrow8x-40=0\)
\(\Leftrightarrow8x=40\)
hay x=5
Vậy: x=5
b) Ta có: \(3x-17=2x-7\)
\(\Leftrightarrow3x-17-2x+7=0\)
\(\Leftrightarrow x-10=0\)
hay x=10
Vậy: x=10
c) Ta có: \(2x-17=-\left(3x-18\right)\)
\(\Leftrightarrow2x-17=-3x+18\)
\(\Leftrightarrow2x-17+3x-18=0\)
\(\Leftrightarrow5x-35=0\)
\(\Leftrightarrow5x=35\)
hay x=7
Vậy: x=7
d) Ta có: \(3x-14=2\left(x-9\right)+1\)
\(\Leftrightarrow3x-14=2x-18+1\)
\(\Leftrightarrow3x-14-2x+18-1=0\)
\(\Leftrightarrow x+3=0\)
\(\Leftrightarrow x=-3\)
Vậy: x=-3
f) Ta có: \(\left(x-5\right)^2=9\)
\(\Leftrightarrow\left[{}\begin{matrix}x-5=3\\x-5=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=2\end{matrix}\right.\)
Vậy: \(x\in\left\{2;8\right\}\)
NJ
11 tháng 2 2018
1.
a, \(x-14=3x+18\)
\(\Rightarrow x-3x=18+14\)
\(\Rightarrow-2x=32\Rightarrow x=\frac{32}{-2}=-16\)
b, \(\left(x+7\right).\left(x-9\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x+7=0\\x-9=0\end{cases}\Rightarrow\orbr{\begin{cases}x=-7\\x=9\end{cases}}}\)
c, \(\left|2x-5\right|-7=22\)
\(\Rightarrow\left|2x-5\right|=22+7\)
\(\Rightarrow\left|2x-5\right|=29\)
\(\Rightarrow\orbr{\begin{cases}2x+5=29\\2x-5=29\end{cases}}\Rightarrow\orbr{\begin{cases}2x=24\\2x=34\end{cases}\Rightarrow}\orbr{\begin{cases}x=12\\x=17\end{cases}}\)
d, \(\left(\left|2x\right|-5\right)-7=22\)
\(\Rightarrow\left(\left|2x\right|-5\right)=29\)
\(\Rightarrow\left|2x\right|=29+5\Rightarrow\left|2x\right|=34\Rightarrow x=\pm17\)
e, \(\left|x+3\right|+\left|x+9\right|+\left|x+5\right|=4x\)
Vì \(\left|x+3\right|\ge0;\left|x+9\right|\ge0;\left|x+5\right|\ge0;4x\ge0\)
Nên \(\left|x+3\right|+\left|x+9\right|+\left|x+5\right|=4x\ge0\)
\(\Rightarrow\left|x+3\right|>0\Rightarrow\left|x+3\right|=x+3\)
\(\left|x+9\right|>0\Rightarrow\left|x+9\right|=x+9\)
\(\left|x+5\right|>0\Rightarrow\left|x+5\right|=x+5\)
Ta có :
\(x+3+x+9+x+5=4x\)
\(\Rightarrow3x+\left(3+9+5\right)=4x\)
\(\Rightarrow4x-3x=17\)
\(\Rightarrow x=17\)
2. a , b sai đề bn
c, \(\left(5x+1\right).\left(y-1\right)=4\)
\(\Rightarrow\left(5x+1\right).\left(y-1\right)\inƯ\left(4\right)\)
\(\text{ }Ư\left(4\right)=\left\{1;-1;2;-2;4;-4\right\}\)
Ta có bảng sau :
| 5x+1 | 1 | -1 | 2 | -2 | 4 | -4 |
| y-1 | -4 | 4 | -2 | 2 | -1 | 1 |
| x | 0 | -2/5 | 1/5 | -3/5 | 3/5 | -1 |
| y | -3 | 5 | -1 | 3 | 0 | 2 |
d, \(5xy-5x+y=5\)
\(\Rightarrow\left(5xy-5x\right)+y=5\)
\(\Rightarrow5x.\left(y-1\right)+y=5\)
\(\Rightarrow\left(5x+1\right).\left(y-1\right)=4\)
\(\Rightarrow\left(5x+1\right).\left(y-1\right)\inƯ\left(4\right)\)
\(Ư\left(4\right)=\left\{1;-1;2;-2;4;-4\right\}\)
Ta có bảng sau :
| 5x+1 | 1 | -1 | 2 | -2 | 4 | -4 |
| y-1 | -4 | 4 | -2 | 2 | -1 | 1 |
| x | 0 | -2 | 1/5 | -3/5 | 3/5 | -1 |
| y | -3 | 5 | -1 | 3 | 0 | 2 |
26 tháng 9 2015
a) \(\frac{5.\left(3x-8\right)}{7.5}=\frac{15x-40}{35}=\frac{35}{9}\)
=> (15x - 40) . 9 = 352
=> 135x - 360 = 1225
=> 135x = 1585
=> x = \(\frac{317}{27}\)
21 tháng 1 2017
1) 10 - 3 ( x - 1 ) = -5
3 ( x - 1 ) = 10 - ( - 5 )
3 ( x - 1 ) = 15
x - 1 = 15 : 3
x - 1 = 5
x = 5 + 1
x = 6
2) 3x + 75 = - 15
3x = - 15 - 75
3x = - 90
x = -90 : 3
x = -30
21 tháng 1 2017
4) 12 - ( x - 7 ) = - 8
x - 7 = 12 - (- 8 )
x - 7 = 20
x = 20 + 7
x = 27
5) x + 75 = 15
x = 15 - 75
x = -60
7) 2x + 18 = 10
2x = 10 - 18
2x = -8
x = - 8 : 2
x = -4
8) 26 - 3x = 5
3x = 26 - 5
3x = 21
x = 21: 3
x = 7
9) x - 12 = - 15
x = -15 + 12
x =-3
10 ) 24 - 2 ( x + 5 ) = 38
2 ( x+ 5 ) = 24 - 38
2 ( x + 5 ) = - 14
x + 5 = -14 : 2
x + 5 = -7
x = -7 - 5
x = -12
còn là bạn tự làm tiếp nhé ! bạn gửi nhiều cầu qua bạn chỉ nên gửi ít một thời như vậy khó có thể giải làm bạn ạ!
14 tháng 6 2023
a: =7/8:(2/9-18+1/36)-5/12
=-7/142-5/12=-397/852
b: =3/7(4/9+5/9:6/12)=2/3
c: =5^8(16/31-47/31)+1/3=-5^8+1/3
d: =7/2(3/8+5/8:4/15)=609/64
a, \(\frac{5}{7}.3x-\frac{8}{5}=\frac{9}{35}\)
=> \(\frac{15}{7}x=\frac{9}{35}+\frac{8}{5}\)=> \(\frac{15}{7}x=\frac{9}{35}+\frac{56}{35}\)
=> \(\frac{15}{7}x=\frac{65}{35}=\frac{13}{7}\)=> \(x=\frac{13}{7}:\frac{15}{7}=\frac{13}{15}\)
vậy \(x=\frac{13}{15}\)
b, \(\frac{2}{9}.5x+\frac{1}{2}-\frac{1}{18}=\frac{5}{36}\)
=> \(\frac{10}{9}x+\frac{1}{2}=\frac{5}{36}+\frac{1}{18}\)=\(\frac{5}{36}+\frac{2}{36}=\frac{7}{36}\)
=> \(\frac{10}{9}x=\frac{7}{36}-\frac{1}{2}\)=\(\frac{7}{36}-\frac{18}{36}\)=\(\frac{-11}{36}\)=> \(x=\frac{-11}{36}:\frac{10}{9}\)=\(\frac{-11}{36}.\frac{9}{10}\)=\(\frac{-11}{40}\)
vậy x=\(\frac{-11}{40}\)
a, ta có : \(\frac{5}{7}.\frac{3x-8}{5}=\frac{9}{35}\Leftrightarrow\frac{3x-8}{5}=\frac{9}{35}:\frac{5}{7}\Leftrightarrow\frac{3x-8}{5}=\frac{9}{35}.\frac{7}{5}\)
\(\Leftrightarrow\frac{3x-8}{5}=\frac{9}{5.5}\Leftrightarrow3x-8=\frac{9}{25}.5\Leftrightarrow3x-8=\frac{9.5}{25}\)
\(\Leftrightarrow3x-8=\frac{9}{5}\Leftrightarrow3x-8=\frac{9}{5}+8\Leftrightarrow3x=\frac{9+8.5}{5}\)
\(\Leftrightarrow3x=\frac{49}{5}\Leftrightarrow x=\frac{49}{5}:3\Leftrightarrow x=\frac{49}{5}.\frac{1}{3}=\frac{49}{15}\)
~ Vậy, ta tìm được \(x=\frac{49}{15}\)
b, Ta có : \(\frac{2}{9}.\frac{5x+1}{2}-\frac{1}{18}=\frac{5}{36}\Leftrightarrow\frac{2}{9}.\frac{5x+1}{2}=\frac{5}{36}+\frac{1}{18}\)
\(\Leftrightarrow\frac{2}{9}.\frac{5x+1}{2}=\frac{5+2.1}{36}\Leftrightarrow\frac{2}{9}.\frac{5x+1}{2}=\frac{7}{36}\)
\(\Leftrightarrow\frac{5x+1}{2}=\frac{7}{36}:\frac{2}{9}\Leftrightarrow\frac{5x+1}{2}=\frac{7}{36}.\frac{9}{2}\Leftrightarrow\frac{5x+1}{2}=\frac{7.9}{4.9.2}\)
\(\Leftrightarrow\frac{5x+1}{2}=\frac{7}{8}\Leftrightarrow5x+1=\frac{7}{8}.2\Leftrightarrow5x+1=\frac{7.2}{8}\)
\(\Leftrightarrow5x+1=\frac{7}{4}\Leftrightarrow5x=\frac{7}{4}-1\Leftrightarrow5x=\frac{7-1.4}{4}\)
\(\Leftrightarrow5x=\frac{3}{4}\Leftrightarrow x=\frac{3}{4}:5\Leftrightarrow x=\frac{3}{4}.\frac{1}{5}\Leftrightarrow x=\frac{3}{20}\)
~ Vậy, ta tìm được \(x=\frac{3}{20}\)