ai giai ho mk voi
(x + 1)2(x + 2) + (x – 1)2(x – 2) = 12
4/x+2 + (-3)/x-2 + 12/x^2-4 giai chi tiet ho mk !
\(\frac{4}{x+2}+\frac{-3}{x-2}+\frac{12}{x^2-4}.\)
\(=\frac{4\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}-\frac{3\left(x+2\right)}{\left(x+2\right)\left(x-2\right)}+\frac{12}{\left(x+2\right)\left(x-2\right)}\)
\(=\frac{4x-8-3x-6+12}{\left(x-2\right)\left(x+2\right)}\)
\(=\frac{x-4}{x^2-4}\)
\(\frac{4}{x+2}+\frac{\left(-2\right)}{x-2}+\frac{12}{x^2-4}\)
\(=\frac{4\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}-\frac{3\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}+\frac{12}{\left(x+2\right)\left(x-2\right)}\)
\(=\frac{4\left(x-2\right)-3\left(x+2\right)+12}{\left(x+2\right)\left(x-2\right)}\)
\(=\frac{x-2}{\left(x+2\right)\left(x-2\right)}\)
\(=\frac{1}{x+2}\)
1/ Tim x
a/x.(x+5) - (x-2)^2 = 4
b/ x.( x+5 ) ( x-5)- (x+2)(x^2 - 2x +4)= 3
c/(x-2)^2 -x (x-8)=12
d/(x-2)^2 -(x+2)^2=11
e/x^2 + 8x -9 = 0
Giai nhanh ho mk nhe
Mk camon
ai onl giai gap cho mk voi nha!
Tim x,y, biet :
\(\left(x+\frac{1}{2}\right)^2+\left(y-\frac{1}{2}\right)^{1998}=0\)
Do \(\left(x+\frac{1}{2}\right)^2\ge0;\left(y-\frac{1}{2}\right)^{1998}\ge0\)
Mà theo đề bài, \(\left(x+\frac{1}{2}\right)^2+\left(y-\frac{1}{2}\right)^{1998}=0\)
=> \(\hept{\begin{cases}\left(x+\frac{1}{2}\right)^2=0\\\left(y-\frac{1}{2}\right)^{1998}=0\end{cases}}\)=> \(\hept{\begin{cases}x+\frac{1}{2}=0\\y-\frac{1}{2}=0\end{cases}}\)=> \(\hept{\begin{cases}x=\frac{-1}{2}\\y=\frac{1}{2}\end{cases}}\)
Vì (x+1/2)^2 và (y-1/2)^1998 luôn lớn hơn hoặc bằng 0
=>(x+1/2)^2=0 và (y-1/2)^1998=0
x+1/2=0 và y-1/2=0
x=-1/2 và y=1/2
Vậy vời x=-1/2 ;y=1/2 thì (x+1/2)^2+(y-1/2)^1998=0
giai chi tiet ho e pt nay voi a. e quen mat cah giai
1/5 x a + 2 + 1/2 x a + 7 = a
giup e voi ạ
Theo đầu bài ta có:
\(\frac{1}{5}\cdot a+2+\frac{1}{2}\cdot a+7=a\)
\(\Rightarrow2+7=a-\frac{1}{2}\cdot a-\frac{1}{5}\cdot a\)
\(\Rightarrow a\cdot\frac{3}{10}=9\)
\(\Rightarrow a=30\)
\(\frac{1}{5}a+2+\frac{1}{2}a+7=a\left(\frac{1}{5}+\frac{1}{2}\right)+2+7=\frac{7}{10}a+10=\frac{7a}{10}+10\)
x.(x-1)+3.(x-1)=0
x.( x-1)-3.(x+1)=0
2. x^2- x=9
2 x^2= x
Giai nhanh gium mk voi
a, x(x-1) + 3(x-1) = 0
<=> (x+3)(x-1) = 0
<=> hoặc x + 3 = 0 hoặc x - 1 = 0
<=> hoặc x = -3 hoặc x = 1
Vậy...
Phan tich da thuc sau thanh nhan tu
a, x^2+2*x*y+y^2-x-y-12
b, 4*x^4-32*x^2+1
c, 3*(x^4+x^2+1)-(x^2+x+1)^2
d,6+x^4+y^4
e, a^6+a^4+a*b^2+b^2-b^6
giai ho mk nha , mk dag can gap=> mon nhiu lem a
3.x +2 : 2.x -1
ban nao giai ho mk vs
3.x có nghĩa là 3 nhân x hả bn????
giai he pt giup mk voi : (xy+y^2)(x+y)=-6 va x(y+1)=-1
giai ho voi
tim min cua
\(A=\frac{\left(x+y+1\right)^2}{xy+x+y}+\frac{xy+x+y}{\left(x+y+1\right)^2}\) (voi x,y la so thuc duong)
Đặt \(\frac{\left(x+y+1\right)^2}{xy+x+y}=a\) ( ĐK a > 0 )
=> A = a + 1/a
(*) \(\left(x+y+1\right)^2\ge3\left(xy+x+y\right)\)( Nhân 2 vế với hai sau đưa về hằng đẳng thức )
=> \(\frac{\left(x+y+1\right)^2}{xy+x+y}\ge3\Leftrightarrow a\ge3\)
TA có \(A=a+\frac{1}{a}=\frac{a}{9}+\frac{1}{a}+\frac{8a}{9}\ge2\sqrt{\frac{a}{9}\cdot\frac{1}{a}}+\frac{8\cdot3}{9}=\frac{2}{3}+\frac{8}{3}=\frac{10}{3}\)
Vậy GTNN của A là 10/3 tại x = y= 1