(x - 1)^x+2 = (x-1)^x +6.
Help me!!!
Tìm x: \(3^{x+2}+4.3^{x+1}+3^{x-1}=6^6\)
HELP ME!
`#3107.\text {DN}`
\(3^{x+2}+4\cdot3^{x+1}+3^{x-1}=6^6\)
`=> 3^x*3^2 + 4*3^x*3 + 3^x * 1/3 = 6^6`
`=>3^x*(3^2 + 12 + 1/3) = 6^6`
`=> 3^x * 64/3 = 6^6`
`=> 3^x = 6^6 \div 64/3`
`=> 3^x = 2187`
`=> 3^x = 3^7`
`=> x = 7`
Vậy, `x = 7.`
bài 2 : tìm X
X x ( X + 1 ) = 2 + 4 + 6 + 8 + 10 + 20
help me
\(x\)\(\times\)( \(x\) + 1) = 2 + 4 + 6 + 8 + 10 + 20
\(x\) \(\times\)(\(x\) + 1) = 50
\(x\) \(\times\)(\(x+1\)) = 2 \(\times\) 5 \(\times\) 5
Nếu \(x\) là số tự nhiên thì không tồn tại
Nếu \(x\) là số thực thì câu hỏi này không phù hợp lớp 5 em nhá
\(x\left(x+1\right)=2+4+6+8+10+20\\ \Leftrightarrow x^2+x-50=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-1-\sqrt{201}}{2}\\x=\dfrac{-1+\sqrt{201}}{2}\end{matrix}\right.\)
Tính:
a) \(\dfrac{1}{2}\) x \(\dfrac{1}{4}\) x \(\dfrac{1}{6}\)
help me
1/5.x-2/3=1/10.x+5/6
[ PLS HELP ME ]
\(\dfrac{1}{5}\times x-\dfrac{2}{3}=\dfrac{1}{10}\times x+\dfrac{5}{6}\)
\(\dfrac{1}{5}x-\dfrac{2}{3}-\dfrac{1}{10}x-\dfrac{5}{6}=0\)
\(\dfrac{1}{5}x-\dfrac{1}{10}x-\dfrac{2}{3}-\dfrac{5}{6}=0\)
\(\dfrac{1}{10}x-\dfrac{3}{2}=0\)
\(\dfrac{1}{10}x=\dfrac{3}{2}\)
\(x=15\)
\(\dfrac{1}{5}\).x - \(\dfrac{2}{3}\) = \(\dfrac{1}{10}\).x + \(\dfrac{5}{6}\)
⇒ \(\dfrac{1}{5}\).x - \(\dfrac{1}{10}\).x = \(\dfrac{5}{6}\) + \(\dfrac{2}{3}\)
⇒ \(\dfrac{2}{10}\).x - \(\dfrac{1}{10}\).x = \(\dfrac{5}{6}\) + \(\dfrac{4}{6}\)
⇒ \(\dfrac{1}{10}\).x = \(\dfrac{9}{6}\)
⇒ x = \(\dfrac{9}{6}\) : \(\dfrac{1}{10}\)
⇒ x = \(\dfrac{9}{6}\) . 10
⇒ x = \(\dfrac{90}{6}\)
⇒ x = 15
Vậy x = 15
timd x thuộc z
(x-1)^x+2=(x-1)^x+6
help me !!!!
\(\left(x-1\right)^{x+2}=\left(x-1\right)^{x+6}\)
Help me
\(\Rightarrow\orbr{\begin{cases}x-1=0\\x-1=1\end{cases}}\Rightarrow\orbr{\begin{cases}x=1\\x=2\end{cases}}\)
Vậy x = 1 hoặc x=2
( x-1)x+2 = (x-1)x+6
( x-1)x+2 - (x-1)x+6 =0
( x-1)x+2 - (x-1)x+2 . (x-1)4 =0
( x-1)x+2 - [1- (x-2)4] =0
TH1: ( x-1)x+2 =0
x-1 = 0
x= 0+1
x = 1
TH2:
1- (x-2)4 =0
(x-2)4 = 1-0
(x-2)4 =1 ( Hai trường hợp vì số mũ là chẵn bạn nhé, mình biểu thị bằng dấu * )
* x-2 = 1 * x-2=-1
x=3 x=1
Vậy x = { 1; 3}
Mình sửa lại dòng 3:
( x-1)x+2 - (x-1)x+2 . (x-1)4 =0
tìm x
-5 nhân ( x+1/5 )-1/2 nhân ( x - 2/3) = 3/2 nhân x - 5/6
help me
Tìm số x ϵ Z bt:
a) (x - 6 )2 = 9 b)42x - 6 = 1
HELP ME!
a) \(\left(x-6\right)^2=9=3^2\)
\(\Rightarrow x-6=3\) hay \(x-6=-3\)
\(\Rightarrow x=9\) hay \(x=3\)
b) \(4^{2x-6}=1=4^0\)
\(\Rightarrow2x-6=0\Rightarrow x=3\)
a) \(\left(x-6\right)^2=9\)
\(\Rightarrow\left(x-6\right)^2=3^2\)
\(\Rightarrow\left[{}\begin{matrix}x-6=-3\\x-6=3\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=6\\x=9\end{matrix}\right.\)
b) \(4^{2x-6}=1\)
\(\Rightarrow4^{2x-6}=4^0\)
\(\Rightarrow2x-6=0\)
\(\Rightarrow2x=6\)
\(\Rightarrow x=3\)
a) Ta có ( x - 6 )2 = 9 = ( \(\pm3\) )2
Nếu ( x - 6 )2 = 32 ⇒ x = 9
Nếu ( x - 6 )2 = ( -3 )2 ⇒ x = 3
Vậy x ϵ { 9; 3 }
b) Ta có 42x - 6 = 1 = 40 ⇒ 2x - 6 = 0 ⇒ x = 3
1 + \(\dfrac{1}{3}\) + \(\dfrac{1}{6}\) + \(\dfrac{1}{10}\)
+......+ \(\dfrac{2}{x(x+1)}\) =1\(\dfrac{1989}{1991}\)
HeLp me