tìm x,biết
a. \(5\times\left(3+7\times x\right)=400\)
b.\(x\times37+x\times63=1200\)
c.\(x\times6+12:3=40\)
d.\(4+6\times x\left(x+1\right)=70\)
e.\(163:x+34:x=10\)
mik sẽ chỉ tick 2 bn thoy vì mik đag cần gấp
Tìm x :
a) x - 5 = 49 : 7
b) 2 \(\times\) x + 6 = 24
c) \(\frac{1}{3}:x+\frac{1}{2}=5\)
d) \(\frac{1}{6}\times x-\frac{1}{3}=2\)
e)\(\frac{x}{27}=\frac{3}{x}\left(vớix\in N\right)\)
g) 1200 : 24 - ( 17 - x ) = 36
h) 674 - ( 12 + x ) = 427
k) 36 \(\times\)( x - 9 ) = 900
m) 1,2 : x + 3,8 : x = 2,5
n) \(\left(\frac{1}{2\times4}+\frac{1}{4\times6}+\frac{1}{6\times8}+\frac{1}{8\times10}\right)\times x=\frac{1}{3}\)
Mik đang cần gấp
Tìm x :
a) \(x-5=49:7\)
\(\Leftrightarrow x-5=7\)
\(\Leftrightarrow x=7+5\)
\(\Leftrightarrow x=12\)
Vậy : \(x=12\)
b) \(2x+6=24\)
\(\Leftrightarrow2x=24-6=18\)
\(\Leftrightarrow x=18:2\)
\(\Leftrightarrow x=9\)
Vậy : \(x=9\)
c) \(\frac{1}{3}:x+\frac{1}{2}=5\)
\(\Leftrightarrow\frac{1}{3}:x=5-\frac{1}{2}=\frac{9}{5}\)
\(\Leftrightarrow x=\frac{1}{3}:\frac{9}{5}\)
\(\Leftrightarrow x=\frac{5}{27}\)
Vậy : \(x=\frac{5}{27}\)
d) \(\frac{1}{6}.x-\frac{1}{3}=2\)
\(\Leftrightarrow\frac{1}{6}.x=2-\frac{1}{3}=\frac{5}{3}\)
\(\Leftrightarrow x=\frac{5}{3}:\frac{1}{6}\)
\(\Leftrightarrow x=10\)
Vậy : \(x=10\)
e) \(\frac{x}{27}=\frac{3}{x}\)
\(\Leftrightarrow x.x=27.3\)
\(\Leftrightarrow x^2=81\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-9\\x=9\end{matrix}\right.\) mà \(x\in N\)
\(\Rightarrow x=9\)
Vậy : \(x=9\)
g) \(1200:24-\left(17-x\right)=36\)
\(\Leftrightarrow50-17+x=36\)
\(\Leftrightarrow33+x=36\)
\(\Leftrightarrow x=36-33\)
\(\Leftrightarrow x=3\)
Vậy : \(x=3\)
h) \(674-\left(12+x\right)=427\)
\(\Leftrightarrow12+x=674-427=247\)
\(\Leftrightarrow x=247-12\)
\(\Leftrightarrow x=230\)
Vậy : \(x=230\)
k) \(36.\left(x-9\right)=900\)
\(\Leftrightarrow x-9=900:36\)
\(\Leftrightarrow x-9=25\)
\(\Leftrightarrow x=25+9\)
\(\Leftrightarrow x=34\)
m) \(1,2:x+3,8:x=2,5\)
\(\Leftrightarrow\left(1,2-3,8\right):x=2,5\)
\(\Leftrightarrow-2,6:x=2,5\)
\(\Leftrightarrow x=\frac{-2,6}{2,5}=-\frac{26}{25}\)
Vậy : \(x=-\frac{26}{25}\)
n) \(\left(\frac{1}{2.4}+\frac{1}{4.6}+\frac{1}{6.8}+\frac{1}{8.10}\right).x=\frac{1}{3}\)
\(\Leftrightarrow\frac{1}{2}.\left(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+\frac{2}{8.10}\right).x=\frac{1}{3}\)
\(\Leftrightarrow\left[\frac{1}{2}.\left(1-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+\frac{1}{8}-\frac{1}{10}\right)\right].x=\frac{1}{3}\)
\(\Leftrightarrow\left[\frac{1}{2}.\left(1-\frac{1}{10}\right)\right].x=\frac{1}{3}\)
\(\Leftrightarrow\frac{1}{2}.\frac{9}{10}.x=\frac{1}{3}\)
\(\Leftrightarrow\frac{9}{20}.x=\frac{1}{3}\)
\(\Leftrightarrow x=\frac{1}{3}:\frac{9}{20}\)
\(\Leftrightarrow x=\frac{20}{27}\)
Vậy : \(x=\frac{20}{27}\)
c)\(\frac{2}{27}\)
d)21
e)81
g)3
k)34
m)2
n)\(\frac{5}{3}\)
Tìm \(x\in Z\):
a. \(2\times\left(x-5\right)-3\times\left(x-4\right)=\left(-6\right)+15\times\left(-3\right)\)
b.\(\left(2x-5\right)-7=22\)
c.\(\left(2\times\left|x\right|-6\right)\times11=44\)
d.\(\left|x+3\right|+\left|x+5\right|+\left|x+9\right|=4x\)
e.\(\left|x-1\right|+\left|x-5\right|=4\)
g.\(x+\left(x+1\right)+\left(x+2\right)+.......+100=0\)
a) x=53
b) x=17
c) x=5;x=-5
d) x=17
e) x=5
g) ???
Tim \(x\in Z\)biet :
a; \(-12\times\left(x-5\right)+7\times\left(3-x\right)=20\)
b; 30\(30\times\left(x+1\right)-3\times\left(x-5\right)-15x=25\)
c; \(|5x-2|\le13\)
mn la on gip mik nha mik dang can gap
a,-12(x-5)+7(3-x)=20
-12x+60+21-7x=20
-19x=-61
x=\(\frac{61}{19}\)
b,30(x+1)-3(x-5)-15x=25
30x+30+15-3x-15x=25
12x=-20
x=\(-\frac{20}{12}\)
\(a,(x\div23+45)\times37-22=2^4\times105\)
\(b,(3x-4)\times(x-1)^3=0\)
\(c,2^{2x-1}\div4=8^3\)
\(d,x^{17}=x\)
\(e,\left(x-5\right)^4=\left(x-5\right)^6\)mình cần gấp
a) tính bình thường thôi
b)\(\left(3x-4\right)\times\left(x-1\right)^3=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x-4=0\\x-1=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{4}{3}\\x=1\end{cases}}\)
c) \(2^{2x-1}:4=8^3\)
\(\Leftrightarrow2^{2x-1}=2048\Leftrightarrow2^{2x-1}=2^{11}\Leftrightarrow2x-1=11\Leftrightarrow x=6\)
d) \(x^{17}=x\Leftrightarrow\orbr{\begin{cases}x=0\\x=1\end{cases}}\)
e) \(\left(x-5\right)^4=\left(x-5\right)^6\)
\(\Leftrightarrow\hept{\begin{cases}x-5=0\\x-5=1\\x-5=-1\end{cases}}\Leftrightarrow\hept{\begin{cases}x=5\\x=6\\x=4\end{cases}}\)
vậy........
a) (x : 23 + 45) . 37 - 22 = 24.105
=> (x : 23 + 45).37 - 22 = 1680
=> (x : 23 + 45).37 = 1702
=> x : 23 + 45 = 46
=> x : 23 = 1
=> x = 23
b) (3x - 4).(x - 1)3 = 0
=> \(\orbr{\begin{cases}3x-4=0\\x-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{4}{3}\\x=1\end{cases}}\)
Vậy \(x\in\left\{\frac{4}{3};1\right\}\)
c) 22x - 1 : 4 = 83
=> 22x - 1 : 22 = (23)3
=> 22x - 1 : 22 = 29
=> 22x - 1 = 211
=> 2x - 1 = 11
=> 2x = 12
=> x = 6
d) x17 = x
=> x17 - x = 0
=> x(x16 - 1) = 0
=> \(\orbr{\begin{cases}x=0\\x^{16}-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\\x^{16}=1\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\\x=\pm1\end{cases}}\)
Vậy \(x\in\left\{0;1;-1\right\}\)
e) (x - 5)4 = (x - 5)6
=> (x - 5)6 - (x - 5)4 = 0
=> (x - 5)4[(x - 5)2 - 1] = 0
=> \(\orbr{\begin{cases}\left(x-5\right)^4=0\\\left(x-5\right)^2-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x-5=0\\\left(x-5\right)^2=1^2\end{cases}}\Rightarrow\orbr{\begin{cases}x-5=0\\x-5=\pm1\end{cases}}\Rightarrow x-5\in\left\{0;1;-1\right\}\)
=> \(x\in\left\{5;6;4\right\}\)
a) \(\left(x:23+45\right)\times37-22=2^4\times105\)
=> \(\left(x:23+45\right)\times37-22=16\times105\)
=> \(\left(x:23+45\right)\times37-22=1680\)
=> (x : 23 + 45) x 37 = 1702
=> x : 23 + 45 = 46
=> x : 23 = 1
=> x = 23
b) \(\left(3x-4\right)\left(x-1\right)^3=0\)
=> \(\orbr{\begin{cases}3x-4=0\\\left(x-1\right)^3=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{4}{3}\\x=1\end{cases}}\)
c) \(2^{2x-1}:4=8^3\)
=> \(2^{2x-1}:2^2=\left(2^3\right)^3\)
=> \(2^{2x-1}=2^9\cdot2^2=2^{11}\)
=> 2x - 1 = 11
=> 2x = 12
=> x = 6
d) \(x^{17}=x\)
=> x17 - x = 0
=> x(x16 - 1) = 0
=> \(\orbr{\begin{cases}x=0\\x^{16}-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=0\\x=1\end{cases}}\)
e) \(\left(x-5\right)^4=\left(x-5\right)^6\)
=> \(\left(x-5\right)^4-\left(x-5\right)^6=0\)
=> \(\left(x-5\right)^4\left[1-\left(x-5\right)^2\right]=0\)
=> \(\orbr{\begin{cases}\left(x-5\right)^4=0\\1-\left(x-5\right)^2=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=5\\\left(x-5\right)^2=1\end{cases}}\)
+) x - 5 = 1 => x = 6 ; x - 5 = -1 => x = 4
Vậy x = 5,x = 6,x = 4
a/\(13-2\times\left(36-5\times x\right)=1\)1
b/ \(53-10\times\left(40-7\times x\right)=3\)
c/\(\frac{3}{4}-\frac{1}{6}\div x=0,375\)
bài mình mới ra sai đề rồi các bạn đừng làm
đề chính xác là
a/ \(13-2\times\left(36-5\times x\right)=1\)
b/ \(53-10\times\left(40-7\times x\right)=3\)
c/ \(\frac{3}{4}-\frac{1}{6}\div x=0,375\)
a) \(13-2\times\left(36-5\times x\right)=1\)
\(2\times\left(36-5\times x\right)=13-1\)
\(2\times\left(36-5\times x\right)=12\)
\(36-5\times x=12\div2\)
\(36-5\times x=6\)
\(5\times x=36-6\)
\(5\times x=30\)
\(x=30\div5\)
\(x=6\)
Tìm x \(\frac{2}{\left(x-1\right)\times\left(x-3\right)}+\frac{5}{\left(x-3\right)\times\left(x-8\right)}+\frac{12}{\left(x-8\right)\times\left(x-20\right)}-\frac{1}{x-20}=-\frac{3}{4}\)-3/4
Các bạn ơi ,giúp mình với
Bài 1:Rút gọn
a)\(\frac{2^{19}\times27^3+15\times4^9\times9^4}{6^9\times2^{10}+12^{10}}\)
b)\(\frac{\left(\frac{-1}{2}\right)^3-\left(\frac{3}{4}\right)^3\times\left(-2\right)^2}{2\times\left(-1\right)^5+\left(\frac{3}{4}\right)^2-\frac{3}{8}}\)
c)\(\frac{45\times9^4-2\times6^4}{2^{19}\times3^8+6^8\times20}\)
Bài 2:Tìm x
a)\(5^x+5^{x+2}=650\)
b)\(3^{x-1}+5\times3=162\)
Bài 1:Tính
1)\(\frac{7}{5}+\frac{-8}{5}\) ; 2)\(\frac{-6}{5}\times\frac{15}{24}\) ; 3) \(\left(\frac{2}{3}+1,5\right)-3,5:7\frac{1}{2}\) ; 4)\(\frac{5}{8}-\frac{-7}{9}\) ; 5)\(\frac{-7}{3}\times\frac{12}{28}\).
Bài 2:Tìm x
1)\(x-70=-45\) ; 2)\(\frac{4}{7}:x=\frac{12}{28}\) ; 3)\(\left(\frac{2}{3}x+1,5\right)-3,5:7\frac{1}{2}\) ;
4)x-50=-35 ;5)\(\frac{4}{7}\times x=\frac{11}{28}\) ;6)\(\left(\frac{2}{3}x+2,5\right):2\frac{2}{6}=6\)
m.n ơi!!!
giúp em vs ạ,e đag cần gấp,e sắp thi r
m.n có trước cho e ngày 28/4/2019 nhé :)
Bài 2 :
1) \(x-70=-45\) 2) \(\frac{4}{7}:x=\frac{12}{28}\)
\(\Rightarrow\) \(x=-45+70\) \(\Rightarrow x=\frac{4}{7}:\frac{12}{28}\)
\(\Rightarrow\) \(x=25\) \(\Rightarrow x=\frac{4}{3}\)
Vậy \(x=25\) Vậy \(x=\frac{4}{3}\)
3) Giống câu c) ở bài 1
4) \(x-50=-35\) 5) \(\frac{4}{7}.x=\frac{11}{18}\)
\(\Rightarrow x=-35+50\) \(\Rightarrow x=\frac{11}{28}:\frac{4}{7}\)
\(\Rightarrow x=15\) \(\Rightarrow x=\frac{77}{72}\)
Vậy \(x=15\) Vậy \(x=\frac{77}{72}\)
6) \(\left(\frac{2}{3}x+2,5\right):2\frac{2}{6}=6\)
\(\Rightarrow\)\(\left(\frac{2}{3}x+2,5\right):\frac{14}{6}=6\)
\(\Rightarrow\) \(\frac{2}{3}x+2,5=6.\frac{14}{6}\)
\(\Rightarrow\frac{2}{3}x+2,5=14\)
\(\Rightarrow\frac{2}{3}x=\frac{23}{2}\)
\(\Rightarrow x=\frac{23}{2}:\frac{2}{3}\)
\(\Rightarrow x=\frac{69}{4}\)
Vậy \(x=\frac{69}{4}\)
Bài 1:
1) \(\frac{7}{5}+\frac{-8}{5}=-\frac{1}{5}\)
2) \(-\frac{6}{5}.\frac{15}{24}=-\frac{3}{4}\)
3) \(\left(\frac{2}{3}+1,5\right)-3,5:7\frac{1}{2}=\)\(\frac{13}{6}-\frac{7}{15}=\frac{17}{10}\)
4) \(\frac{5}{8}-\frac{-7}{9}=\frac{5}{8}+\frac{7}{9}=\frac{101}{72}\)
5)\(\frac{-7}{3}.\frac{12}{28}=-1\)
cho: \(f\left(x\right)=a\times x^3+4\times x\times\left(x^2-1\right)+8\)
\(g\left(x\right)=x^3-4\times x\times\left(b\times x+1\right)+c-3\)
tìm a, b, c để \(f\left(x\right)=g\left(x\right)\)