\(\left(^{x^2}\times y\right)^{^5}\times\left(x^2\times y^2\right)^7\times\left(x\times y^2\right)^6\times x^3\)
cho 2 đa thức \(A=2\times x^2\times y^3-3\times x^3\times y^2+x^2\times y^2+1\)
\(B=2\times x^2\times y^3-3\times x^3\times y^2-x^2\times y^2+2\)
Tính \(2\times A-\left(B-\left(A-\left(-4\times B\right)\right)\right)\)
Tìm x,y biết
\(\left(x-3\right)^2+\left(y+2\right)^2=0\)
\(2\times x+2^{x+3}=136\)
\(\left(x-12+y\right)^{200}+\left(x-4-y\right)^{200}=0\)
\(\left(2\times x-5\right)^{2000}+\left(3\times y+4\right)^{2002}\le0\)
\(\left(x-3\right)^2+\left(y+2\right)^2=0\)
\(\left\{{}\begin{matrix}\left(x-3\right)^2\ge0\forall x\\\left(y+2\right)^2\ge0\forall y\end{matrix}\right.\)
\(\Rightarrow\left(x-3\right)^2+\left(y+2\right)^2\ge0\)
Dấu "=" xảy ra khi:
\(\left\{{}\begin{matrix}\left(x-3\right)^2=0\Rightarrow x-3=0\Rightarrow x=3\\\left(y+2\right)^2=0\Rightarrow y+2=0\Rightarrow y=-2\end{matrix}\right.\)
đề sai câu b các câu sau áp dụng tương tự
c/ Vì: \(\left(x-12+y\right)^{200}+\left(x-4-x\right)^{200}=0\)
mà \(\left\{{}\begin{matrix}\left(x-12+y\right)^{200}\ge0\forall x,y\\\left(x-4-y\right)^{200}\ge0\forall x,y\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\left(x-12+y\right)^{200}=0\\\left(x-4-y\right)^{200}=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x-12+y=0\\x-4-y=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x+y=12\\x-y=4\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=8\\y=4\end{matrix}\right.\)
tìm x \(6\times\left(x-\frac{1}{y}\right)=3\times\left(y-\frac{1}{z}\right)=2\times\left(z-\frac{1}{x}\right)\)
rút gọn :
a,\(\frac{x^5y}{\left(xy^4\right)}\)
b, \(\frac{3\times x^2\times y^5}{9\times x\times y^4}\)
c, \(\frac{\left(3\times x\times y^2\right)^4}{27\times x^5y^3}\)
\(\frac{x^5y}{xy^4}=\frac{x^4}{y^3}\)
\(\frac{3\times x^2\times y^5}{9\times x\times y^4}=\frac{xy}{3}\)
1.Rút gọn biểu thức:
\(a,\)\(x\times\left(2x^2-3\right)-x^2\left(5x+1\right)+x^2\)
\(b,\)\(3x\times\left(x-2\right)-5x\times\left(1-x\right)-8\times\left(x^2-3\right)\)
\(c,\)\(\left(2x-6\right)\times\left(x+3\right)-5\times\left(2x^2-x+7\right)\)
1)Phân tích đa thức sau thành nhân tử ;
a)\(x^3+\left(a+b+c\right)\times x^2+\left(ab+ac+bc\right)\times x+abc\)
b)\(x\times\left(y^2-z^2\right)+y\left(z^2-x^2\right)-z\left(x^2-y^2\right)\)
a) x3 + (a+b+c)x2+ (ab+ac+bc)x +abc
= x3 +ax2+bx2+cx2+abx+acx+bcx+abc
=x3+cx2+abx+abc+ax2+acx+bx2+bcx
=x2 (x+c) + ab (x+c) +ax (x+c) +bx (x+c)
= (x+c) (x2+ab+ax+bx)
= (x+c) { x(x+b)+a(x+b)}
=(x+c) (x+b) (x+a)
Tìm y biết:
\(\left\{\begin{matrix}x\times\left(x-y+z\right)=5\\y\times\left(y-z-x\right)=24\\z\times\left(z+x-y\right)=7\end{matrix}\right.\)
\(2\times\left(x-y\right)\times\left(x+y\right)+\left(x+y\right)^2+\left(x-y\right)\)
Rut gon
\(\left(2\times X-y\right)^5+\left(2\times y-8\right)=0\\ \)