Tìm x:
a) x : 11 = 78
Tìm x:
a) x * 2 + x * 3 = 60
b) x * 15 – x * 9 = 78
a) x * 2 + x * 3 = 60
x * ( 2 + 3 ) = 60
x = 60 : 5
x = 12
b) x * 15 - x * 9 = 78
x * ( 15 - 9 ) = 78
x = 78 : 6
x = 13
Tìm x:
a) 1 = (2x + 0,5)600
b) (x - 0,125)2 = 0,25
c) (x - 3)11 = (x - 3)41
a) \(1=\left(2x+0,5\right)^{600}\)
\(\Rightarrow1^{600}=\left(2x+0,5\right)^{600}\)
\(\Rightarrow\left[{}\begin{matrix}2x+0,5=1\\2x+0,5=-1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=0,5\\2x=-1,5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0,25\\x=-0,75\end{matrix}\right.\)
b) \(\left(x-0,125\right)^2=0,25\)
\(\Rightarrow\left(x-0,125\right)^2=0,5^2\)
\(\Rightarrow\left[{}\begin{matrix}x-0,125=0,5\\x-0,125=-0,5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0,625\\x=-0,375\end{matrix}\right.\)
c) \(\left(x-3\right)^{11}=\left(x-3\right)^{41}\)
\(\Rightarrow\left(x-3\right)^{11}-\left(x-3\right)^{41}=0\)
\(\Rightarrow\left(x-3\right)^{11}\left[1-\left(x-3\right)^{30}\right]=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(x-3\right)^{11}=0\\\left(x-3\right)^{30}=1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x-3=0\\x-3=1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\)
`@` `\text {Ans}`
`\downarrow`
`a)`
`1 = (2x + 0,5)^600`
`=> (2x+0,5)^600 = (+-1)^600`
`=> \text {TH1: } 2x + 0,5 = 1`
`=> 2x = 1 - 0,5`
`=> 2x = 0,5`
`=> x = 0,5 \div 2`
`=> x = 0,25`
`\text {TH2: } 2x + 0,5 = -1`
`=> 2x = -1 - 0,5`
`=> 2x = -1,5`
`=> x = -1,5 \div 2`
`=> x = -0,75`
Vậy, `x \in {-0,75; 0,25}.`
`b)`
`(x - 0,125)^2 = 0,25`
`=> (x - 0,125)^2 = (+-0,5)^2`
`=> `\(\left[{}\begin{matrix}x-0,125=0,5\\x-0,125=-0,5\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=0,5+0,125\\x=-0,5+0,125\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=0,625\\x=-0,375\end{matrix}\right.\)
Vậy, `x \in {-0,375; 0,625}.`
`c)`
`(x - 3)^11 = (x - 3)^41`
`=> (x - 3)^11 - (x - 3)^41 = 0`
`=> (x - 3)^11 * [ 1 - (x - 3)^30] = 0`
`=>`\(\left[{}\begin{matrix}\left(x-3\right)^{11}=0\\1-\left(x-3\right)^{30}=0\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x-3=0\\\left(x-3\right)^{30}=1\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=3\\x-3=1\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=3\\x=4\end{matrix}\right.\)
Vậy, `x \in {3; 4}.`
a, 1=(2x+0,5)600
=>1600=(2x+0,5)600
=>1=2x+0,5
=>2x+0,5=1
=> 2x= 1+0,5
=>2x= 1,5
=:>x= 1,5:2
=>x=0,75
b, (x-0,125)2=0,25
=>(x-0,125)2=(0,5)2
=>x-0,125=0,5
=>x=0,5 +0,125
=>x= 0,625
c, (x-3)11=(x-3)41
(x-3)11 -(x-3)41=0
(x-3)11-(x-3)11 .(x-3)30=0
(x-3)11.[1-(x-3)30 ]=0
(x-3)11.(4-x)30=0
(x-3)11=0 hoặc (4-x)30=0
(x-3)11=0 ( 4-x)30=0
x-3=0 4-x=0
x=0+3 x=4-0
x=3 x=4
vậy xϵ{3,4}
Tìm x:
a, (-5) +x = 7
b, (-14) - x + (-15) = -10
c, 12 + x (-5) = -18
d, x - (-19) - (-11) = 0
Tìm x:
a) √x = 3
b) √x = 6
c) √x = 8
d) √x = 12
e) 2√x = 10
f) 3√x = 21
g) √x = 8
h) 2 + √x = 11
\(a,\sqrt{x}=3\Leftrightarrow x=9\\ b,\sqrt{x}=6\Leftrightarrow x=36\\ c,\sqrt{x}=8\Leftrightarrow x=64\\ d,\sqrt{x}=12\Leftrightarrow x=144\\ e,2\sqrt{x}=10\Leftrightarrow\sqrt{x}=5\Leftrightarrow x=25\\ f,3\sqrt{x}=21\Leftrightarrow\sqrt{x}=7\Leftrightarrow x=49\\ g,\sqrt{x}=8\Leftrightarrow x=64\\ h,2+\sqrt{x}=11\Leftrightarrow\sqrt{x}=9\Leftrightarrow x=81\)
a. \(\sqrt{x}=3\)
<=> \(\left(\sqrt{\sqrt{x}}\right)^2-\left(\sqrt{3}\right)^2=0\)
<=> \(\left(\sqrt{\sqrt{x}}-\sqrt{3}\right)\left(\sqrt{\sqrt{x}}+\sqrt{3}\right)=0\)
<=> \(\left[{}\begin{matrix}\sqrt{\sqrt{x}}-\sqrt{3}=0\\\sqrt{\sqrt{x}}+\sqrt{3}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=9\\x=\left(Vnghiêm\right)\end{matrix}\right.\)
Vậy nghiệm của PT là S = \(\left\{9\right\}\)
a) \(\sqrt{x}=3\Leftrightarrow x=9\)
b) \(\sqrt{x}=6\Leftrightarrow x=36\)
c) \(\sqrt{x}=8\Leftrightarrow x=64\)
d) \(\sqrt{x}=12\Leftrightarrow x=144\)
e) \(2\sqrt{x}=10\Leftrightarrow\sqrt{x}=5\Leftrightarrow x=25\)
f) \(3\sqrt{x}=21\Leftrightarrow\sqrt{x}=7\Leftrightarrow x=49\)
g) \(\sqrt{x}=8\Leftrightarrow x=64\)
h) \(2+\sqrt{x}=11\Leftrightarrow\sqrt{x}=9\Leftrightarrow x=81\)
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. 1/3+x=5/6
b.|x-1|-2/5=11/10 c.1/3+2/3(x/2+3)=1
d.x+2/3 = 27/x+2
a.\(\dfrac{1}{3}\) + x = \(\dfrac{5}{6}\)
x = \(\dfrac{5}{6}\) - \(\dfrac{1}{3}\)
x = \(\dfrac{1}{2}\)
b. | x-1| - \(\dfrac{2}{5}\) = \(\dfrac{11}{10}\)
| x-1| = \(\dfrac{11}{10}\) + \(\dfrac{2}{5}\)
|x-1| = \(\dfrac{3}{2}\)
\(\left[{}\begin{matrix}x-1=\dfrac{3}{2}\\x-1=-\dfrac{3}{2}\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=\dfrac{3}{2}+1\\x=-\dfrac{3}{2}+1\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)
c, \(\dfrac{1}{3}\) + \(\dfrac{2}{3}\) ( \(\dfrac{x}{2}\) + 3) = 1
\(\dfrac{2}{3}\) (\(\dfrac{x}{2}\) + 3) = 1 - \(\dfrac{1}{3}\)
\(\dfrac{2}{3}\) ( \(\dfrac{x}{2}\) + 3) = \(\dfrac{2}{3}\)
\(\dfrac{x}{2}\) + 3 = 1
\(\dfrac{x}{2}\) = 1 - 3
\(\dfrac{x}{2}\) = -2
\(x\) = -4
d, \(\dfrac{x+2}{3}\) = \(\dfrac{27}{x+2}\)
(x+2)2 = 27.3
(x+2) =92
\(\left[{}\begin{matrix}x+2=9\\x+2=-9\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=7\\x=-11\end{matrix}\right.\)
Tìm x:
a) [2040 : (47 - 3x) + 33] . 11 = 1683
\(\left[2040:\left(47-3x\right)+33\right].11=1683\)
\(\Leftrightarrow2040:\left(47-3x\right)+33=153\)
\(\Leftrightarrow2040\left(47-3x\right)=120\)
\(\Leftrightarrow47-3x=17\)
\(\Leftrightarrow3x=30\Leftrightarrow x=10\)
tìm x:a.1+(1+2x)+(1+3x)+...+(1+19x)=417
b.10+(11+x)+(12+2x)+(13+3x)+...+(19+9x)=190
Tìm x:
a) x : 11 = 25;
b) x : 11 = 78
a) x : 11 = 25
x = 25 x 11
x = 275
b) x : 11 = 78
x = 78 x 11
x = 858
a) 4524-(864-999)-(36+3999) b)-12(x-5)+7(3-x)=5 c)512.(2-128)-128.(-512) d)2155-(174+2155)+(-68+174)
e)-78+11.(97-99) f)512.(2-128)-128.(-512)
tìm x:a)32x+42=35-(-70) b)3|x-5|=21 c)15x=-75.
lay may tinh bam la xong
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