Help me =(
Tìm x:
a, 111 × x – x × 11 = 10800
b, 42 : x + 35 : x = 11
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 và y biết 42/x=-35/y và x-y=11
\(\frac{42}{x}=\frac{-35}{y}=\frac{42+35}{x-y}=\frac{77}{11}=7\)
\(\Rightarrow\) x = 6; y = - 5
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}
tính bằng cách thuận tiện nhất:
35 x 11 + 42 x 11 + 22 x 11 + 11
giúp mình với
=11 x (35 + 42 + 22 + 1)
=11 x 100
=1100
học tốt em nhé
35 x 11+42x11+22x11+11
= (35 + 42 + 22 +11 ) x11 =
= 110 x11
=1210
Help me tìm x biết : (x - 21 x 13 ) : 11+ 39 = 50
(x - 21 x 13) : 11 + 39 = 50
(x - 273) : 11 = 50 - 39
(x - 273) : 11 = 11
x - 273 = 11 x 11
x - 273 = 121
x = 121 + 273
x = 394
vậy x = 394
[ x - 21 x 13 ] : 11 + 39 = 50
[ x - 273 ] : 11 = 50 - 39
[x - 273 ] : 11 = 11
x - 273 = 11 x 11
x - 273 = 121
x = 121 + 273
x = 394
\(\left(x-21\cdot13\right):11+39=50\)
\(\frac{x}{11}-\frac{34}{11}+39=50\)
\(\frac{x}{11}=\frac{155}{11}\)
\(x=155\)
Tìm x:
a, X x 5 = 9,5 b, 42 x X = 15,12
a: 5x=9,5
nên x=1,9
b: 42x=15,12
nên x=15,12:42=0,36
a, \(x=\dfrac{9,5}{5}=\dfrac{19}{10}\)
b, \(x=\dfrac{15,12}{42}=\dfrac{9}{25}\)
a.\(x\times5=9,5\)
\(\Rightarrow x=9,5:5=1,9\)
b.\(42\times x=15,12\)
\(\Rightarrow x=15,12:42=0,36\)
Tìm x thuộc Z biết :
( x + 1 ) + ( x + 3 ) + ( x + 5 ) +... + ( x +90 ) = 0
(x-3)+(x-2)+(x-1)+...+ 10 + 11 = 11
:(
Help me !
Cần gấp !
sai đề
(x+1 ) + (x+3)+..........+(x+99)=0
=> x + 1 + x + 3 + x + 5 + ........... + x + 99 = 0
Từ 1-->99 có số số hạng là:
(99-1):2+1=50(số)
Tổng từ 1 -->99 là:
(99+1) x 50:2=2500
=> 50x + 2500=0
=>50x=-2500
=>x=-50
Câu 2 mình k hiểu đề
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
\(\left[{}\begin{matrix}x+2=9\\x+2=-9\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=7\\x=-11\end{matrix}\right.\)