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a) \(\frac{-2}{3}x+\frac{1}{5}=\frac{1}{10}\)
\(\Leftrightarrow\frac{-2}{3}x=\frac{1}{10}-\frac{1}{5}\)
\(\Leftrightarrow\frac{-2}{3}x=\frac{-1}{10}\)
\(\Leftrightarrow x=\frac{-1}{10}\div\frac{-2}{3}\)
\(\Leftrightarrow x=\frac{3}{20}\)
\(\dfrac{5}{x}+1+\dfrac{4}{x}+1=\dfrac{3}{-13}\\ \Rightarrow\dfrac{9}{x}+2=-\dfrac{3}{13}\\ \Rightarrow\dfrac{9}{x}=-\dfrac{59}{13}\\ \Rightarrow x=-\dfrac{207}{59}\)
a. \(\dfrac{5}{x+1}+\dfrac{4}{x+1}=\dfrac{-3}{13}\)
ĐKXĐ: x ≠ -1
⇔ \(\dfrac{65}{13\left(x+1\right)}+\dfrac{52}{13\left(x+1\right)}=\dfrac{-3\left(x+1\right)}{13\left(x+1\right)}\)
⇔ 65 + 52 = -3(x + 1)
⇔ 117 = -3x - 3
⇔ 117 + 3 = -3x
⇔ 120 = -3x
⇔ x = \(\dfrac{120}{-3}=-40\) (TM)
b. -x + 2 + 2x + 3 + x + \(\dfrac{1}{4}\) + 2x + \(\dfrac{1}{6}\) = \(\dfrac{8}{3}\)
⇔ -x + 2x + x + 2x = \(\dfrac{8}{3}-\dfrac{1}{6}-\dfrac{1}{4}-3-2\)
⇔ 4x = -2,75
⇔ x = \(\dfrac{-2,75}{4}=\dfrac{-11}{16}\)
c. \(\dfrac{3}{2x+1}+\dfrac{10}{4x+2}-\dfrac{6}{6x+2}\) = \(\dfrac{12}{26}\)
⇔ \(\dfrac{3}{2x+1}+\dfrac{10}{2\left(2x+1\right)}-\dfrac{6}{2\left(3x+1\right)}=\dfrac{12}{26}\)
⇔ \(\dfrac{312\left(3x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\) + \(\dfrac{520\left(3x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\) - \(\dfrac{312\left(2x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\)
= \(\dfrac{48\left(2x+1\right)\left(3x+1\right)}{104\left(2x+1\right)\left(3x+1\right)}\)
⇔ 312(3x +1) + 520(3x + 1) - 312(2x + 1) = 48(2x + 1)(3x + 1)
⇔ 936x + 312 + 1560x + 520 - 624x - 312 = (96x + 48)(3x + 1)
⇔ 936x + 312 + 1560x + 520 - 624x - 312 = 288x2 + 96x + 144x + 48
⇔ 936x + 1560x - 624x - 96x - 144x - 288x2 = 48 - 312 - 520 + 312
⇔ 1632x - 288x2 = -472
⇔ -288x2 + 1632x + 472 = 0 (Tự giải tiếp, dùng phương pháp tách hạng tử)
⇔ x = 5,942459684 \(\approx\) 6
a,(2x+7)+135=0 b, 1/2x-2/5=1/5
2x+7=0-135 1/2x=1/5+2/5
2x+7=-135 1/2x=3/5
2x=-135-7 x=3/5:1/2
2x=-142 x=6/5
x=-142:2 Vậy x=6/5
x=-71
Vậy x=-71
c, 10-|x+1|=5 d, 1/2x+150%x=2014
|x+1|=10-5 2x=2014
|x+1|=5 x=2014:2
*TH1:x+1=5 *TH2:x+1=-5 x=1007
x=5-1 x=-5-1 Vậy x=1007
x=4 x=-6
Vậy x=4 hoặc x=-6
a/2.5x+1+10=60
2.5x+1=50
5x+1=25
5x+1=55
x+1=5
x=6
b/(x-1)2=4
(x-1)2=22 hoặc (x-1)2 = (-2)2
x-1=2 hoặc x-1=-2
x=3 hoặc x=-1
c/ (2x+1)2=25
(2x+1)2=52 hoặc (2x+1)2=(-5)2
2x+1=5 hoặc 2x+1 = -5
2x=4 hoặc 2x=-6
x=2 hoặc x=-3
câu d hình như đề sai
a)2.5x+1+10=60 ➩2.5x+1=60-10=50 ➩5x+1=50:2=25 ➩5x+1=52 ➩x+1=2 ➩x=1
b)(x-1)2=4 ➩x-1=2 hoặc x-1=-2 ➩x=3 hoặc x=-1
*phần b,c mình ghi "hoặc" thì bạn dùng dấu ngoặc vuông nhé *
C)(2x+1)2=25. ➩(2x+1)2=52 ➩2x+1=5 hoặc 2x+1=-5
➩x=2 hoặc x=-3
Phần D là 2x+2x+3=144 hay 2x+2x+3 =144 thế
\(x\div4\frac{1}{3}=-2,5\)
\(\Leftrightarrow x\div\frac{13}{3}=\frac{-5}{2}\)
\(\Leftrightarrow x=\frac{-5}{2}.\frac{13}{3}\)
\(\Leftrightarrow x=\frac{-65}{6}\)
\(x\div\frac{-3}{5}=\frac{-10}{21}\)
\(\Leftrightarrow x=\frac{-10}{21}.\frac{-3}{5}\)
\(\Leftrightarrow x=\frac{30}{105}\)
\(\Leftrightarrow x=\frac{2}{7}\)
\(\frac{2}{3}x-\frac{1}{2}=\frac{1}{10}\)
\(\Leftrightarrow\frac{2}{3}x=\frac{1}{10}+\frac{1}{2}\)
\(\Leftrightarrow\frac{2}{3}x=\frac{6}{10}\)
\(\Leftrightarrow x=\frac{6}{10}\div\frac{2}{3}\)
\(\Leftrightarrow x=\frac{18}{20}\)
\(\Leftrightarrow x=\frac{9}{10}\)
\(\frac{1}{2}x+\frac{1}{2}=\frac{5}{2}\)
\(\Leftrightarrow\frac{1}{2}\left(x+1\right)=\frac{5}{2}\)
\(\Leftrightarrow\left(x+1\right)=\frac{5}{2}\div\frac{1}{2}\)
\(\Leftrightarrow\left(x+1\right)=5\)
\(\Leftrightarrow x=5-1\)
\(\Leftrightarrow x=4\)
1: Ta có: \(20-2\left(x+4\right)=4\)
\(\Leftrightarrow2\left(x+4\right)=16\)
\(\Leftrightarrow x+4=8\)
hay x=4
5: Ta có: \(\left(x+1\right)^3=27\)
\(\Leftrightarrow x+1=3\)
hay x=2
a) \(x=\dfrac{25}{72}\)
b)\(x=-\dfrac{1}{4}\)
\(x=\dfrac{3}{2}\)
c)\(x=\dfrac{5}{4}\) hoặc
x \(=\dfrac{8}{5}\)
d và e chịu vì mk kg giỏi lắm về mũ
f)\(x=-2\)
G)\(x=-\dfrac{5}{12}\)
a. => \(2^{6+x}=2^{10}\)
=> 6+x=10
=> x=10-6
Vậy x=4.
b. => \(7^{3x-1}:7^2=7^6\)
=> 73x-1-2=76
=> 73x-3=76
=> 3x-3=6
=> 3x=6+3
=> 3x=9
Vậy x=3.
c. =>\(7^{5x-1}-25=24\)
=>75x-1=24+25
=>75x-1=49
=>75x-1=72
=>5x-1=2
=>5x=3
Vậy x=\(\frac{3}{5}\).
d. => \(10^{x-3}=10^0\)
=>x-3=0
Vậy x=3.
e. => 2x=10
=> x=10:2
Vậy x=5.
`#3107`
b)
`2.3^x = 162`
`\Rightarrow 3^x = 162 \div 2`
`\Rightarrow 3^x = 81`
`\Rightarrow 3^x = 3^4`
`\Rightarrow x = 4`
Vậy, `x = 4`
c)
`(2x - 15)^5 = (2 - 15)^3`
\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`
\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`
\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)
Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)
`d)`
\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!
`e)`
\(7\cdot4^{x-1}+4^{x-1}=23?\)
\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)
Bạn xem lại đề!
`f)`
\(2\cdot2^{2x}+4^3\cdot4^x=1056\)
\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)
Vậy, `x = 2`
_____
\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)
\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)
\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)
\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)
\(\Rightarrow\left(x\div3+17\right)\div10=2\)
\(\Rightarrow x\div3+17=20\)
\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)
Vậy, `x = 9.`
a) \(3x-10=2x+13\)
\(\Leftrightarrow3x-2x=13+10\)
\(\Leftrightarrow x=23\)
b) \(x+12=-5-x\)
\(\Leftrightarrow x+x=-5-12\)
\(\Leftrightarrow2x=-17\)
\(\Leftrightarrow x=-\frac{17}{2}\)
c) \(x+5=10-x\)
\(\Leftrightarrow x+x=10-5\)
\(\Leftrightarrow2x=5\)
\(\Leftrightarrow x=\frac{5}{2}\)
d) \(6x+2^3=2x-12\)
\(\Leftrightarrow6x+8=2x-12\)
\(\Leftrightarrow6x-2x=-12-8\)
\(\Leftrightarrow4x=-20\)
\(\Leftrightarrow x=-5\)
e) \(12-x=x+1\)
\(\Leftrightarrow-x-x=1-12\)
\(\Leftrightarrow-2x=-11\)
\(\Leftrightarrow x=\frac{11}{2}\)
g) \(2\left(x-1\right)+3\left(x-2\right)=x-4\)
\(\Leftrightarrow2x-2+3x-6=x-4\)
\(\Leftrightarrow2x+3x-x=-4+6+2\)
\(\Leftrightarrow4x=4\)
\(\Leftrightarrow x=1\)
h) \(14+4x=3x+20\)
\(\Leftrightarrow4x-3x=20-14\)
\(\Leftrightarrow x=6\)
i) \(4\left(2x+7\right)-3\left(3x-2\right)=24\)
\(\Leftrightarrow8x+28-9x+6=24\)
\(\Leftrightarrow8x-9x=24-6-28\)
\(\Leftrightarrow-x=-10\)
\(\Leftrightarrow x=10\)
k) \(3\left(4-x\right)-2\left(x-1\right)=x+20\)
\(\Leftrightarrow12-3x-2x+2=x+20\)
\(\Leftrightarrow-3x-2x-x=20-2-12\)
\(\Leftrightarrow-6x=6\)
\(x=-1\)
l) \(3\left(x-2\right)+2x=10\)
\(\Leftrightarrow3x-6+2x=10\)
\(\Leftrightarrow3x+2x=10+6\)
\(\Leftrightarrow5x=16\)
\(\Leftrightarrow x=\frac{16}{5}\)
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