x^2 - 9
Giúp mik :/
a)|x|-9=-2+17
b)|x-9|=-2+17
giúp mik với mik cần gấp
a)|x|-9=-2+17
|x|-9 = 15
|x| = 15 + 9
|x| = 24
\(\Rightarrow x=\mp24\)
b)|x-9|=-2+17
|x-9| = 15
\(\Rightarrow\orbr{\begin{cases}x-9=15\\x-9=-15\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x=24\\x=-6\end{cases}}\)
Hok tốt !
a)|x|-9=-2+17
| x| -9 = 15
| x | = 15 + 9
| x| = 24
Vậy x= 24 hoặc x = -24
b)|x-9|=-2+17
| x -9| = 15
Th1: x - 9 = 15
x = 15 + 9
x = 24
Th2 : x - 9 = -15
x = -15 + 9
x = -6
vậy x = 24 hoặcx = -6
hok tốt!!!
Bài giải
a, \(\left|x\right|-9=-2+17\)
\(\left|x\right|-9=15\)
\(\left|x\right|=15+9\)
\(\left|x\right|=24\)
\(x\in\left\{\pm24\right\}\)
b, \(\left|x-9\right|=-2+17\)
\(\left|x-9\right|=15\)
\(\Rightarrow\orbr{\begin{cases}x-9=-15\\x-9=15\end{cases}}\Rightarrow\orbr{\begin{cases}x=-6\\x=24\end{cases}}\)
\(\Rightarrow\text{ }x\in\left\{-6\text{ ; }24\right\}\)
x/15+x/12=4/1+1/2=9/2 giúp mik vs mik đag cần trl gấp
\(\dfrac{x}{15}\)+\(\dfrac{x}{12}\)=4/1+1/2=9/2
=>x(\(\dfrac{1}{15}\)+\(\dfrac{1}{12}\))=9/2
=>x\(\cdot\)\(\dfrac{3}{20}\)=9/2
=>x=9/2:3/20=30
Vậy x=30
\(\dfrac{x}{15}+\dfrac{x}{12}=\dfrac{9}{2}\Rightarrow\left(\dfrac{1}{15}+\dfrac{1}{12}\right)x=\dfrac{9}{2}\)
\(\Rightarrow\left(\dfrac{12+18}{180}\right)x=\dfrac{9}{2}\Rightarrow\dfrac{30}{180}x=\dfrac{9}{2}\Rightarrow\dfrac{1}{6}x=\dfrac{9}{2}\Rightarrow x=\dfrac{9}{2}.6=27\)
2/5+x=15/20
8/9-2/9:x =2/3
giúp mik với ai lam dung mik tick cho
2/5 + x = 15/20
2/5 + x = 3/4
x = 3/4 - 2/5
x = 7/20
8/9 - 2/9 : x = 2/3
2/9 : x = 8/9 - 2/3
2/9 : x = 2/9
x = 2/9 : 2/9
x = 1
\(\frac{2}{5}+x=\frac{15}{20}\)
\(\frac{2}{5}+x=\frac{3}{4}\)
\(x=\frac{3}{4}-\frac{2}{5}\)
\(x=\frac{7}{20}\)
\(\frac{8}{9}-\frac{2}{9}:x=\frac{2}{3}\)
\(\frac{2}{9}:x=\frac{8}{9}-\frac{2}{3}\)
\(\frac{2}{9}:x=\frac{2}{9}\)
\(x=\frac{2}{9}:\frac{2}{9}\)
\(x=1\)
Mik làm chi tiết nhé, bạn có thể lược 1 số phần nếu thích
\(\frac{2}{5}+x=\frac{15}{20}\)
=>\(\frac{2}{5}+x=\frac{3}{5}\)
=>\(x=\frac{3}{5}-\frac{2}{5}\)
=> \(x=\frac{1}{5}\)
\(\frac{8}{9}-\frac{2}{9}:x=\frac{2}{3}\)
=> \(\frac{8}{9}-\frac{2}{9}:x=\frac{6}{9}\)
=> \(\frac{2}{9}:x=\frac{8}{9}-\frac{6}{9}\)
=>\(\frac{2}{9}:x=\frac{2}{9}\)
=> \(x=\frac{2}{9}:\frac{2}{9}\)
=> \(x=1\)
a/ \(\dfrac{-3}{5}\) - x = \(\dfrac{21}{10}\)
b/ x : \(\dfrac{2}{9}\) = \(\dfrac{9}{2}\)
c/ \(\dfrac{x}{9}\) = \(\dfrac{5}{3}\)
d/ x : \(\left(\dfrac{2}{5}\right)^3\)= \(\left(\dfrac{5}{2}\right)^3\)
giúp mik gấp nha, mik sắp thi rồi!
\(\dfrac{-3}{5}-x=\dfrac{21}{10}\)
\(x=\dfrac{-3}{5}-\dfrac{21}{10}\)
\(x=\)-\(\dfrac{27}{10}\)
\(x:\dfrac{2}{9}=\dfrac{9}{2}\)
\(x.\dfrac{9}{2}=\dfrac{9}{2}\)
\(x=\dfrac{9}{2}:\dfrac{9}{2}\)
\(x=1\)
\(\dfrac{x}{9}=\dfrac{5}{3}\)
\(x.3=5.9\)
\(x.3=45\)
\(x=45:3=15\)
\(x:\left(\dfrac{2}{5}\right)^3=\left(\dfrac{5}{2}\right)^3\)
\(x:\dfrac{8}{125}=\dfrac{125}{8}\)
\(x.\dfrac{125}{8}=\dfrac{125}{8}\)
\(x=\dfrac{125}{8}:\dfrac{125}{8}=1\)
\(\sqrt{x^2-2x+4}+\sqrt{x^2+5}=9-2x\)
Làm giúp mik bài này với ạ mik cảm mơn
\(\sqrt{x^2-2x+4}+\sqrt{x^2+5}=9-2x\left(đk:x\le\dfrac{9}{2}\right)\)
\(\Leftrightarrow x^2-2x+4+x^2+5+2\sqrt{\left(x^2-2x+4\right)\left(x^2+5\right)}=81-36x+4x^2\)
\(\Leftrightarrow2\sqrt{\left(x^2-2x+4\right)\left(x^2+5\right)}=2x^2-34x+72\)
\(\Leftrightarrow4\left(x^2-2x+4\right)\left(x^2+5\right)=4x^4+1156x^2+5184-136x^3+288x^2-4896x\)
\(\Leftrightarrow4x^4-8x^3+36x^2-40x+80=4x^4-136x^3+1444x^2-4896x+5184\)
\(\Leftrightarrow128x^3-1408x^2+4856x-5104=0\)
\(\Leftrightarrow128x^2\left(x-2\right)-1152x\left(x-2\right)+2552\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(128x^2-1152x+2552\right)=0\)
\(\Leftrightarrow x=2\left(tm\right)\)(do \(128x^2-1152x+2552>0\))
bài 2:tìm x,biết:
a)x+3/9=7/6x2/3
b)x-2/3=1/8:5/4
giải ra giúp mik vs ạ! mik cảm ơn...mik đag cần gấp
a: \(x+\dfrac{3}{9}=\dfrac{7}{6}\cdot\dfrac{2}{3}\)
=>\(x+\dfrac{1}{3}=\dfrac{14}{18}=\dfrac{7}{9}\)
=>\(x=\dfrac{7}{9}-\dfrac{1}{3}=\dfrac{7}{9}-\dfrac{3}{9}=\dfrac{4}{9}\)
b: \(x-\dfrac{2}{3}=\dfrac{1}{8}:\dfrac{5}{4}\)
=>\(x-\dfrac{2}{3}=\dfrac{1}{8}\cdot\dfrac{4}{5}=\dfrac{1}{10}\)
=>\(x=\dfrac{1}{10}+\dfrac{2}{3}=\dfrac{3+20}{30}=\dfrac{23}{30}\)
\(9\left(x-1\right)^2-\dfrac{4}{9}:\dfrac{2}{9}=\dfrac{1}{4}\)
giúp mik y
\(\Rightarrow9\left(x-1\right)^2-2=\dfrac{1}{4}\\ \Rightarrow9\left(x-1\right)^2=\dfrac{9}{4}\\ \Rightarrow\left(x-1\right)^2=4\\ \Rightarrow\left[{}\begin{matrix}x-1=2\\1-x=2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)
giải giúp mik với a) 2^x+1 =64
b) 570-x: 3 và 17<x<20
c) (4x-9)-(x+111)=0
giúp mik với nha mik cần gấp
\(a,2^{x+1}=64\\ \Rightarrow a,2^{x+1}=2^6\\ \Rightarrow x+1=6\\ \Rightarrow x=5\)
\(b,x=18\)
\(c,\left(4x-9\right)-\left(x+111\right)=0\\ \Rightarrow4x-9-x-111=0\\ \Rightarrow3x-120=0\\ \Rightarrow3x=120\\ \Rightarrow x=40\)
a
,
2
x
+
1
=
64
⇒
a
,
2
x
+
1
=
2
6
⇒
x
+
1
=
6
⇒
x
=
5
b
,
x
=
18
c
,
(
4
x
−
9
)
−
(
x
+
111
)
=
0
⇒
4
x
−
9
−
x
−
111
=
0
⇒
3
x
−
120
=
0
⇒
3
x
=
120
⇒
x
=
40
x+2/x^2+3x - x+1/x^2 -9
giúp mik nha
=x+2/x(x+3)-x+1/(x+3)(x-3)
=(x+2)(x-3)/x(x+3)(x-3)-(x+1)x/x(x-3)(x+3)
=(x+2)(x-3)-x(x+1)/x(x-3)(x+3)
=x^2-x-6-x^2-x/x(x-3)(x+3)
=-2x-6/x(x-3)(x+3)
=-2(x+3)/x(x-3)(x+3)
=-2/x(x-3)
2 x 3 x 4 x 6 x 7 x 8 x 9 = ??
cô mik cho bài tập giúp mik nha
Thế thì bằng 362880
Sửa lại nè :
2 x 3 x 4 x 5 x 6 x 7 x 8 x 9
= 326 880
Hok tốt
= 362880 nhuhu