tim x de : -(\(\sqrt{x}\)-1) * p = 2 * \(\sqrt{x+2}\)
biet p = -(\(\sqrt{x}\)- 1)
cac ban giai ho minh mk dang can gap
tim x biet;
/x+1/2/+/x+1/6/+.......+/x+1/110/=11*x
Cac ban trinh bay that day du nhe
Cac ban lam nhanh ho minh,minh dang can gap
Theo bài ra ta có:
|x+\(\frac{1}{2}\)|\(\ge\)0
|x+\(\frac{1}{6}\)|\(\ge\)0
............................
|x+\(\frac{1}{110}\)|\(\ge\)0
\(\Rightarrow\)|x+\(\frac{1}{2}\)|+|x+\(\frac{1}{6}\)|+...+|x+\(\frac{1}{110}\)|\(\ge\)0
\(\Rightarrow\)11.x\(\ge\)0
\(\Rightarrow\)x\(\ge\)0
\(\Rightarrow\)x dương.
Khi đó:|x+\(\frac{1}{2}\)|+|x+\(\frac{1}{6}\)|+...+|x+\(\frac{1}{110}\)|=11.x
\(\Rightarrow\)x+\(\frac{1}{2}\)+x+\(\frac{1}{6}\)+...+x+\(\frac{1}{110}\)=11.x
\(\Rightarrow\)27.x+\(\left(\frac{1}{2}+\frac{1}{6}+...+\frac{1}{110}\right)\)=11x
\(\Rightarrow\)\(\left(\frac{1}{2}+\frac{1}{6}+...+\frac{1}{110}\right)\)=-16x
\(\Rightarrow\)\(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{10.11}\)=-16x
\(\Rightarrow\)\(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{10}-\frac{1}{11}\)=-16x
\(\Rightarrow\)\(\frac{10}{11}\)=-16x
\(\Rightarrow\)\(\frac{10}{-176}=x\)
Vậy \(x=\frac{10}{-176}\).
cho bieu thuc P= (\(\frac{3x+\sqrt{9x}-3}{x+\sqrt{x}-2}+\frac{1}{\sqrt{x}-1}+\frac{1}{\sqrt{x}-3}\) ): \(\frac{1}{x-1}\)
a) Tim dieu kien de P co nghia, rut gon bieu thuc P.
b) Tim cac so tu nhien x de \(\frac{1}{P}\)la so tu nhien
c) Tinh gia tri cua P voi x= 4-\(2\sqrt{3}\)
Giup mk vs mk dang can gap
Cho A=\(\frac{\sqrt{x}+1}{\sqrt{x}-5}\)Tim x de A la mot so nguyen
Minh dang can cau tra loi som cam on cac ban
\(\frac{\sqrt{x}+1}{\sqrt{x}-5}\inℤ\Leftrightarrow6⋮\sqrt{x}-5\Leftrightarrow\sqrt{x}-5\in\left\{-1;1;2;-2;-3;3;-6;6\right\}\)
\(\Leftrightarrow\sqrt{x}\in\left\{4;6;7;3;2;8;-1;11\right\}\Leftrightarrow x\in\left\{16;36;49;9;4;64;1;121\right\}\)
tim x biet
\(\sqrt{x-7}=x-1\)
mk dg can gap, ai giai ki gium mk nha
tim x biet N thuoc
a) 2-(x+3)=1+2+3+4+5+..............+99
b)(x+1)+(x+2)+(x+3)+(x+4)+...............+(x+100)=5750
giup mk nha cac ban , mk dang can gap lam
a) 2-(x+3) = 1+2+3+...+99
1+2+3+...+99 → có 99 số hạng
2-(x+3) = (1+99).99 : 2
2-(x+3) = 4950
x+3 = 2 + 4950
x+3 = 4952
x = 4952 - 3
x = 4949
b) (x+1)+(x+2)+...+(x+100) = 5750
→ có 100 cặp
(x+x+x+...+x) + ( 1+2+3+...+100 ) = 5750
=> 100x + 5050 = 5750
100x = 5750 - 5050
100x = 700
x = 700 : 100
x = 7
0o0 Nguyễn Đoàn Tuyết Vy 0o0 bà kêu tui học tốt có nghĩa là học giốt đúng ko
b)(x+1)+(x+2)+(x+3)+(x+4)+...............+(x+100)=5750
(x+x+x+x+...+x) + (1+2+3+4+...+100) = 5750
100x + 5050 = 5750
100x = 5750 - 5050
100x = 700
x = 700 : 100
x = 7
Vậy ...
(2x+3)(x-5)=4x2+6x
cac ban giai ho minh minh dang can gap
pt <=> ( 2x + 3 )( x - 5 ) - 2x( 2x + 3 ) = 0
<=> ( 2x + 3 )( -x - 5 ) = 0
<=> x = -3/2 hoặc x = -5
Vậy ...
\(\left(2x+3\right)\left(x-5\right)=4x^2+6x\Leftrightarrow\left(2x+3\right)\left(x-5\right)=2x\left(2x+3\right)\)
\(\Leftrightarrow\left(2x+3\right)\left(-x-5\right)=0\Leftrightarrow x=-\frac{3}{2};x=-5\)
Vậy tập nghiệm của pt là S = { -5 ; -3/2 }
tim max cua\(\sqrt{14-x}+\sqrt{x-10}\).
cac ban giup minh giai nhe, minh can rất gấp ạ
\(A=\sqrt{14-x}+\sqrt{x-10}\)
Đk:\(10\le x\le14\)
\(A^2=\left(\sqrt{14-x}+\sqrt{x-10}\right)^2\)
\(=\left(14-x\right)+\left(x-10\right)+2\sqrt{\left(14-x\right)\left(x-10\right)}\)
\(=4+2\sqrt{\left(14-x\right)\left(x-10\right)}\)
\(\le4+\left(14-x\right)+\left(x-10\right)\) (BĐT AM-GM)
\(=4+4=8\Rightarrow A^2\le8\Rightarrow A\le\sqrt{8}\)
Bai 5
1/ Tim GTNN : A= x^2+3x+2
2/Tim x,y biet:
a/x^2-4x+y^2+2y+5=0
b/2x^2+y^2-2xy+10x+25=0
Giai ho minh bai 1,2,3,4,5 nhe !!! Minh dang len tren dien dan roi day !!!!
Minh can gap !!! Camon may ban tr'c nha
\(x^2+3x+2\) =\(x^2+2.\frac{3}{2}x+\left(\frac{3}{2}\right)^2-\frac{5}{4}\)=\(\left(x+\frac{3}{2}\right)^2-\frac{5}{4}\ge-\frac{5}{4}\)
Dấu "=" xảy ra <=>\(x+\frac{3}{2}=0\)<=>\(x=-\frac{3}{2}\)
Bài 2:
a) \(x^2-4x+y^2+2y+5=0\)
=> \(\left(x^2-4x+4\right)+\left(y^2+2y+1\right)=0\)
=>\(\left(x-2\right)^2+\left(y+1\right)^2=0\)
Vì \(\left(x-2\right)^2+\left(y+1\right)^2\ge0\)nên:
=>\(\hept{\begin{cases}x-2=0\\y+1=0\end{cases}}\)<=>\(\hept{\begin{cases}x=2\\y=-1\end{cases}}\)
b)\(2x^2+y^2-2xy+10x+25=0\)
=>\(\left(x^2-2xy+y^2\right)+\left(x^2+10x+25\right)=0\)
=>\(\left(x-y\right)^2+\left(x+5\right)^2=0\)
Tới đây thì dễ nhá !
Mih nhầm nhá, câu a là -1/4 cơ nha bạn
phan a nghia la so nao la 1 thi thay bang 1/4 a ???
Cac ban oi giup minh voi
tim x biet 6.4/x=x/99tim cac so nguyen biet (|x|-3)(x^2+4) be hon hoac bang 4hai dia diem a va b cach nhau 90kmhai nguoi di xe dap cung mot luc tu ava bde gap nhau va ho gap nhau cach a 50km;nhung neu nguoi di tu b di nhanh hon xuat phat truoc nguoi a 1 gio thi ho gap nhau cach a 350/9km tinh van toc moi nguoiCac giai ho minh voi minh se tick cho
Cac ban nho viet ho cach lam min voi