Tìm x, biết: (x -2)5 - ( x - 2)3 = 0
Giúp mik với mn ơi! Mình cần gấp lắm!
\(\left(x-2\right)^5-\left(x-2\right)^3=0\)
\(\Rightarrow\left(x-2\right)^3\left(\left(x-2\right)^2-1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x-2=0\\\left(x-2\right)^2-1=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\\left(x-2\right)^2=1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x-2=1\\x-2=-1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=3\\x=1\end{matrix}\right.\)
Vậy \(x\in\left\{1;2;3\right\}\)
⇒ ( x - 2)3 . (x - 2)2 - (x - 2)3 . 1 = 0 ⇒ ( x - 2)3 . [( x - 2)2 - 1] = 0
Bạn Nguyễn Đức Trí ơi, cảm ơn bạn đã trả lời giúp mik nhưng mik thấy cô mik dạy là x chỉ thuộc { 2 ; 3 } thôi nhé bạn!
ai giúp mình với, mn làm nhanh giúp mình nhé! mình cảm ơn nhiều
tìm x,y,z biết:
1) x+2/3 = y-7/5 và x + y = 21
2) x+5/2 = y-2/3 và x - y = -10
1. áp dụng tính chất của dãy tỉ số bằng nhau ta có :
\(\frac{x+2}{3}=\frac{y-7}{5}=\frac{x+y-5}{3+5}=\frac{16}{8}=2\Rightarrow\hept{\begin{cases}x+2=6\\y-7=10\end{cases}\Leftrightarrow\hept{\begin{cases}x=4\\y=17\end{cases}}}\)
2. áp dụng tính chất của dãy tỉ số bằng nhau ta có :
\(\frac{x+5}{2}=\frac{y-2}{3}=\frac{x+5-y+2}{2-3}=\frac{-10+7}{-1}=3\Rightarrow\hept{\begin{cases}x+5=6\\y-2=9\end{cases}}\Leftrightarrow\hept{\begin{cases}x=1\\y=11\end{cases}}\)
tìm x biết: 4/5(2/3.x-9/5)-2/5.-3/7=15/4 giúp mình vs MN
\(\dfrac{4}{5}\left(\dfrac{2}{3}x-\dfrac{9}{5}\right)-\dfrac{2}{5}\cdot\dfrac{-3}{7}=\dfrac{15}{4}\)
\(\Rightarrow\dfrac{2}{5}\left(\dfrac{2}{3}x-\dfrac{9}{5}\right)-\dfrac{-6}{35}=\dfrac{15}{4}\)
\(\Rightarrow\dfrac{2}{5}\left(\dfrac{2}{3}x-\dfrac{9}{5}\right)+\dfrac{6}{35}=\dfrac{15}{4}\)
\(\Rightarrow\dfrac{2}{5}\left(\dfrac{2}{3}x-\dfrac{9}{5}\right)=\dfrac{15}{4}-\dfrac{6}{35}=\dfrac{501}{140}\)
\(\Rightarrow\dfrac{2}{3}x-\dfrac{9}{5}=\dfrac{501}{140}:\dfrac{2}{5}=\dfrac{501\cdot5}{28\cdot5\cdot2}=\dfrac{501}{56}\)
\(\Rightarrow\dfrac{2}{3}x=\dfrac{501}{56}+\dfrac{9}{5}=\dfrac{2001}{280}\)
\(\Rightarrow x=\dfrac{2001}{280}:\dfrac{2}{3}=\dfrac{2001\cdot3}{280\cdot2}=\dfrac{6003}{560}\)
Tìm x biết 4x(x-5)-(x-1) (4x-3)-5=0 mn giúp mình với
`4x(x-5)-(x-1) (4x-3)-5=0`
`=> 4x*x - 4x*5 - ( x*4x-3*x-1*4x+ 1*3) -5=0`
`=> 4x^2 - 20x-(4x^2 -3x-4x+3)-5=0`
`=> 4x^2 - 20x-4x^2+3x+4x-3-5=0`
`=>-13x-8=0`
`=> -13x=8`
`=> x=-8/13`
Vậy `x=-8/13`
`4x(x-5)-(x-1)(4x-3)-5 = 0`
`=> 4x^2 - 20x - (4x^2 -3x-4x+3)= 5`
`=> 4x^2 - 20x - 4x^2 + 3x + 4x -3 = 5`
`=> (4x^2 - 4x^2) - (20x - 3x - 4x) = 8`
`=> -13x = 8`
`=> x = -8/13`
Tìm x E N biết:
a) 5x + 5x + 2 = 650
b) 3x - 1 + 5 x 3x -1 = 162
Mn giúp mình với. Mình đang cần gấp
a)5x +5x+2=650
=> 5x+5x. 52 =650
=> 5x(1+52)=650
=> 5x. 26=650
=> 5x=25
=> x= 2
b) 3x-1 +5 x 3 x-1 = 162
=> 3 x-1 (5 +1) = 162
=> 3 x-1 x 6 = 162
=> 3 x-1 = 27
=> x-1 =3
=> x =2
Tìm số hữu tỉ x biết
a)4x+5(x-3)=3
b)-3(x-5)+6(x+2)=9
Mn ơi giúp mình vs ạ
a) 4x + 5(x - 3) = 3
<=> 4x + 5x - 15 = 3
<=> 9x = 3 + 15
<=> 9x = 18
<=> x = 2
b) -3(x - 5) + 6(x + 2) = 9
<=> -3x + 15 + 6x + 12 = 9
<=> 3x + 27 = 9
<=> 3x = -18
<=> x = -6
tìm x biết 2.x+3/5.x+2=4.x+5/10.x+2
giúp mình với
bài 9:tìm x
1) (x-3)^2-4=0
2) x^2-2x=24
3) (2x-1)^2+(x+3)^3-5(x+7)(x-7)=0
giúp mình với mn ơi
1) \(\left(x-3\right)^2-4=0\)
\(\Leftrightarrow\left(x-3-2\right)\left(x-3+2\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=1\end{matrix}\right.\)
2) \(x^2-2x=24\)
\(\Leftrightarrow x^2-2x-24=0\)
\(\Leftrightarrow x^2+4x-6x-24=0\)
\(\Leftrightarrow x\left(x+4\right)-6\left(x+4\right)=0\)
\(\Leftrightarrow\left(x+4\right)\left(x-6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-4\end{matrix}\right.\)
Mn giúp mình với ạ!Mình cảm ơn!
3/2.(x-5/3)-4/5=x+1
\(\dfrac{3}{2}\)(\(x\) - \(\dfrac{5}{3}\)) - \(\dfrac{4}{5}\) = \(x\) + 1
\(\dfrac{3}{2}\) \(x\) - \(\dfrac{15}{6}\) - \(\dfrac{4}{5}\) = \(x\) + 1
\(\dfrac{3}{2}\)\(x\) - \(x\) = 1 + \(\dfrac{15}{6}\) + \(\dfrac{4}{5}\)
\(\dfrac{1}{2}\)\(x\) =\(\dfrac{43}{10}\)
\(x\) = \(\dfrac{43}{10}\) \(\times\) 2
\(x\) = \(\dfrac{43}{5}\)
\(\dfrac{3}{2}\left(x-\dfrac{5}{3}\right)-\dfrac{4}{5}=x+1\\ \Rightarrow\dfrac{3.\left(x-\dfrac{5}{3}\right)}{2}-\dfrac{4}{5}=x+1\\ \Rightarrow\dfrac{3x-5}{2}-\dfrac{4}{5}=x+1\Rightarrow\dfrac{5\left(3x-5\right)}{10}-\dfrac{8}{10}=x+1\\ \Rightarrow\dfrac{15x-33}{10}=x+1\\ \Rightarrow\dfrac{15x-33}{10}-x=x+1\\ \Rightarrow\dfrac{15x-33}{10}=x+1-x\\ \Rightarrow5x-33=10\\ \Rightarrow5x=10+33\\\Rightarrow5x=43\\ \Rightarrow x=\dfrac{43}{5} \)
\(\dfrac{3}{2}\times\left(x-\dfrac{5}{3}\right)-\dfrac{4}{5}=x+1\)
\(\Leftrightarrow\dfrac{3}{2}\times x-\dfrac{5}{2}-\dfrac{4}{5}=x+1\)
\(\Leftrightarrow\dfrac{3}{2}\times x-x=1+\dfrac{5}{2}+\dfrac{4}{5}\)
\(\Leftrightarrow\dfrac{1}{2}\times x=\dfrac{43}{10}\)
\(\Leftrightarrow x=\dfrac{43}{10}\div\dfrac{1}{2}\)
\(\Leftrightarrow x=\dfrac{43}{5}\)