Thực hiện phép tính:
a) (x-2) (3x+1) (x+1)
b) \(\left(x^3+x^2y+xy^2+y^3\right)\left(x-y\right)\)
c) \(-\left(2x-y\right)\left(4x^2+2xy+y^2\right)\)
Những câu hỏi liên quan
Thực hiện phép tính:a) dfrac{2}{5}xyleft(x^2y-5x+10yright)b) left(x^2-1right)left(x^2+2x+yright)c) left(x+3yright)^2d) left(4x-yright)^3e) left(x^2-2yright)left(x^2+2yright)g) 18x^4y^2z:10x^4yh) left(x^3y^3+dfrac{1}{2}x^2y^3-x^3y^2right):dfrac{1}{3}x^2y^2i) left(6x^3-7x^2-x+2right):left(2x+1right)k) dfrac{5x-1}{3x^2y}+dfrac{x+1}{3x^2y}l) dfrac{3x+1}{x^2-3x+1}+dfrac{x^2-6x}{x^2-3x+1}m) dfrac{2x+3}{10x-4}+dfrac{5-3x}{4-10x}n) dfrac{x}{x^2+2x+1}+dfrac{3}{5x^2-5}o) dfrac{x^2+2}{x^3-1}+dfrac{2}{x^2+x...
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Thực hiện phép tính:
a) \(\dfrac{2}{5}xy\left(x^2y-5x+10y\right)\)
b) \(\left(x^2-1\right)\left(x^2+2x+y\right)\)
c) \(\left(x+3y\right)^2\)
d) \(\left(4x-y\right)^3\)
e) \(\left(x^2-2y\right)\left(x^2+2y\right)\)
g) \(18x^4y^2z:10x^4y\)
h) \(\left(x^3y^3+\dfrac{1}{2}x^2y^3-x^3y^2\right):\dfrac{1}{3}x^2y^2\)
i) \(\left(6x^3-7x^2-x+2\right):\left(2x+1\right)\)
k) \(\dfrac{5x-1}{3x^2y}+\dfrac{x+1}{3x^2y}\)
l) \(\dfrac{3x+1}{x^2-3x+1}+\dfrac{x^2-6x}{x^2-3x+1}\)
m) \(\dfrac{2x+3}{10x-4}+\dfrac{5-3x}{4-10x}\)
n) \(\dfrac{x}{x^2+2x+1}+\dfrac{3}{5x^2-5}\)
o) \(\dfrac{x^2+2}{x^3-1}+\dfrac{2}{x^2+x+1}+\dfrac{1}{1-x}\)
p) \(\dfrac{4x+2}{15x^3y}\dfrac{5y-3}{9x^2y}+\dfrac{x+1}{5xy^3}\)
q) \(\dfrac{2x-7}{10x-4}-\dfrac{3x+5}{4-10x}\)
r) \(\dfrac{3}{2x+6}-\dfrac{x-6}{2x^2+6x}\)
x) \(\dfrac{4y^2}{11x^4}.\left(-\dfrac{3x^2}{8y}\right)\)
y) \(\dfrac{x^2-4}{3x+12}.\dfrac{x+4}{2x-4}\)
z) \(\left(x^2-25\right):\dfrac{2x+10}{3x-7}\)
t) \(\left(\dfrac{2x+1}{2x-1}-\dfrac{2x-1}{2x+1}\right):\dfrac{4x}{10x-5}\)
w) \(\left(\dfrac{1}{x^2+x}-\dfrac{2-x}{x+1}\right):\left(\dfrac{1}{x}+x-2\right)\)
c: \(=x^2+6xy+9y^2\)
e: \(=x^4-4y^2\)
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SGK Chân trời sáng tạo
22 tháng 7 2023 lúc 8:25
Thực hiện các phép nhân:
a) \(3x\left( {2xy - 5{x^2}y} \right)\) b) \(2{x^2}y\left( {xy - 4x{y^2} + 7y} \right)\)
c) \(\left( { - \frac{2}{3}xy^2 + 6y{z^2}} \right).\left( { - \frac{1}{2}xy} \right)\)
`a)`
`3x(2xy - 5x^2y)`
`= 3x*2xy + 3x* (-5x^2y)`
`= 6x^2y - 15x^3y`
`b)`
`2x^2y (xy - 4xy^2 + 7y)`
`= 2x^2y * xy + 2x^2y * (-4xy^2) + 2x^2y * 7y`
`= 2x^3y^2 - 8x^3y^3 + 14x^2y^2`
`c)`
`(-2/3xy^2 + 6yz^2)*(-1/2xy)`
`= (-2/3xy^2)*(-1/2xy) + 6yz^2 * (-1/2xy)`
`= 1/3x^2y^3 - 3xy^2z^2`
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`a, 3x(2xy-5x^2y)`
`= 6x^2y - 15x^3y`
`b, 2x^2y(xy-4xy^2+7y)`
`= 2x^3y^2 - 8x^3y^3 + 14x^2y^2`
`c, (-2/3xy^2 + 6yz^2).(-1/2xy)`
`= 1/3x^2y^3 - 3xy^2z^2`
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Thực hiện phép tính:a) dfrac{x+2y}{xy}divdfrac{x^2+4xy+4y^2}{2x^2}b) dfrac{4x^3-xy^2}{x^2+xy+y^2}divdfrac{left(2x-yright)^3}{x^3-y^3}c) dfrac{x+3}{x+2}divdfrac{3x+9}{2x-1}divdfrac{4x-2}{2x+4}d) dfrac{x+1}{x+2}divleft(dfrac{2x^2}{2x-3}timesdfrac{3x+3}{4x^3}right)
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Thực hiện phép tính:
a) \(\dfrac{x+2y}{xy}\div\dfrac{x^2+4xy+4y^2}{2x^2}\)
b) \(\dfrac{4x^3-xy^2}{x^2+xy+y^2}\div\dfrac{\left(2x-y\right)^3}{x^3-y^3}\)
c) \(\dfrac{x+3}{x+2}\div\dfrac{3x+9}{2x-1}\div\dfrac{4x-2}{2x+4}\)
d) \(\dfrac{x+1}{x+2}\div\left(\dfrac{2x^2}{2x-3}\times\dfrac{3x+3}{4x^3}\right)\)
a: \(=\dfrac{x+2y}{xy}\cdot\dfrac{2x^2}{\left(x+2y\right)^2}=\dfrac{2x}{y\left(x+2y\right)}\)
b: \(=\dfrac{x\left(4x^2-y^2\right)}{x^2+xy+y^2}\cdot\dfrac{\left(x-y\right)\left(x^2+xy+y^2\right)}{\left(2x-y\right)^3}\)
\(=\dfrac{x\left(x-y\right)\left(2x+y\right)\left(2x-y\right)}{\left(2x-y\right)^3}\)
\(=\dfrac{x\left(x-y\right)\left(2x+y\right)}{\left(2x-y\right)^2}\)
c: \(=\dfrac{x+3}{x+2}\cdot\dfrac{2x-1}{3\left(x+3\right)}\cdot\dfrac{2\left(x+2\right)}{2\left(2x-1\right)}\)
=1/3
d: \(=\dfrac{x+1}{x+2}:\left(\dfrac{1}{2x}\cdot\dfrac{3x+3}{2x-3}\right)\)
\(=\dfrac{x+1}{x+2}\cdot\dfrac{2x\left(2x-3\right)}{3\left(x+1\right)}=\dfrac{2x\left(2x-3\right)}{3\left(x+2\right)}\)
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Thực hiện các phép tính :
a) left(dfrac{9}{x^3-9x}+dfrac{1}{x+3}right):left(dfrac{x-3}{x^2+3x}-dfrac{x}{3x+9}right)
b) left(dfrac{2}{x-2}-dfrac{2}{x+2}right).dfrac{x^2+4x+4}{8}
c) left(dfrac{3x}{1-3x}+dfrac{2x}{3x+1}right):dfrac{6x^2+10x}{1-6x+9x^2}
d) left(dfrac{x}{x^2-25}-dfrac{x-5}{x^2+5x}right):dfrac{2x-5}{x^2+5x}+dfrac{x}{5-x}
e) left(dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+dfrac{y}{x^2+y^2}right):left(dfrac{1}{x-y}-dfrac{2xy}{x^3-x^2y+xy^2-y^3}right)
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Thực hiện các phép tính :
a) \(\left(\dfrac{9}{x^3-9x}+\dfrac{1}{x+3}\right):\left(\dfrac{x-3}{x^2+3x}-\dfrac{x}{3x+9}\right)\)
b) \(\left(\dfrac{2}{x-2}-\dfrac{2}{x+2}\right).\dfrac{x^2+4x+4}{8}\)
c) \(\left(\dfrac{3x}{1-3x}+\dfrac{2x}{3x+1}\right):\dfrac{6x^2+10x}{1-6x+9x^2}\)
d) \(\left(\dfrac{x}{x^2-25}-\dfrac{x-5}{x^2+5x}\right):\dfrac{2x-5}{x^2+5x}+\dfrac{x}{5-x}\)
e) \(\left(\dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+\dfrac{y}{x^2+y^2}\right):\left(\dfrac{1}{x-y}-\dfrac{2xy}{x^3-x^2y+xy^2-y^3}\right)\)
giải HPT
a) \(\left\{{}\begin{matrix}\left(x+3\right)\left(y-5\right)=xy\\\left(2x-y\right)\left(y+15\right)=2xy\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}\sqrt{4x}-3y+4z^2=-2\\\sqrt{3x}+2y-3z^2=1\\-3\sqrt{x}+y+2z^2=4\end{matrix}\right.\)
\(\left\{{}\begin{matrix}x^3y\left(1+y\right)+x^2y^2\left(2+y\right)+xy^3=30\\x^2y+x\left(1+y+y^2\right)+y=11\end{matrix}\right.\)
Ta có hpt \(\left\{{}\begin{matrix}xy+3y-5x-15=xy\\2xy+30x-y^2-15y=0\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}5x=3y-15\\6\left(3y-15\right)-y^2-15y=0\end{matrix}\right.\)
Ta có pt (2) \(\Leftrightarrow3y-y^2-80=0\Leftrightarrow y^2-3y+80=0\left(VN\right)\)
=> hpy vô nghiệm
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c) Ta có hpt \(\Leftrightarrow\left\{{}\begin{matrix}xy\left(x+y\right)\left(xy+x+y\right)=30\\xy\left(x+y\right)+xy+x+y=11\end{matrix}\right.\)
Đặt j\(xy\left(x+y\right)=a;xy+x+y=b\), ta có hpt
\(\left\{{}\begin{matrix}ab=30\\a+b=11\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}a=5;b=6\\a=6;b=5\end{matrix}\right.\)
với a=5;b=6, ta có \(\left\{{}\begin{matrix}xy\left(x+y\right)=5\\xy+x+y=6\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}xy=1;x+y=5\\xy=5;x+y=1\end{matrix}\right.\)
đến đây thì thế y hoặc x ra pt bậc 2, còn TH còn lại bn tự giải nhé !
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b) Ta có hpt <=> \(\left\{{}\begin{matrix}2\sqrt{x}-3y+2=-4z^2\\2\sqrt{3x}+4y-2=6z^2\\-3\sqrt{x}+y-4=-2z^2\end{matrix}\right.\)
cộng 3 vế của 3 pt, ta có \(\left(2\sqrt{3}-1\right)\sqrt{x}=4\Leftrightarrow\sqrt{x}=\dfrac{4}{2\sqrt{3}-1}\Leftrightarrow x=\dfrac{16}{\left(2\sqrt{3}-1\right)^2}\)
đến đây thay căn(x)=...vào và đặt z^2=m, ta sẽ ra 1 hệ mới chỉ có 2 ẩn y và m bậc 1 , lát thế vào sẽ ra bậc 2 thì dễ rồi !
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giải hệ phương trình
a) left{{}begin{matrix}sqrt{2x^2+2y^2}+sqrt{frac{4}{3}left(x^2+xy+y^2right)}2left(x+yright)sqrt{3x+1}+sqrt{5x+4}3xy-y+3end{matrix}right.
b) left{{}begin{matrix}sqrt{5x^2+2xy+2y^2}+sqrt{2x^2+2xy+5y^2}3left(x+yright)sqrt{x+2y+1}+2sqrt[3]{12x+7y+8}2xy+x+5end{matrix}right.
c)left{{}begin{matrix}x^2+xy+x+30left(x+1right)^2+3left(y+1right)+2left(xy-sqrt{x^2y+2y}right)0end{matrix}right.
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giải hệ phương trình
a) \(\left\{{}\begin{matrix}\sqrt{2x^2+2y^2}+\sqrt{\frac{4}{3}\left(x^2+xy+y^2\right)}=2\left(x+y\right)\\\sqrt{3x+1}+\sqrt{5x+4}=3xy-y+3\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}\sqrt{5x^2+2xy+2y^2}+\sqrt{2x^2+2xy+5y^2}=3\left(x+y\right)\\\sqrt{x+2y+1}+2\sqrt[3]{12x+7y+8}=2xy+x+5\end{matrix}\right.\)
c)\(\left\{{}\begin{matrix}x^2+xy+x+3=0\\\left(x+1\right)^2+3\left(y+1\right)+2\left(xy-\sqrt{x^2y+2y}\right)=0\end{matrix}\right.\)
b)\(\sqrt{5x^2+2xy+2y^2}+\sqrt{2x^2+2xy+5y^2}=3\left(x+y\right)\)
\(\Rightarrow\left(\sqrt{5x^2+2xy+2y^2}+\sqrt{2x^2+2xy+5y^2}\right)^2=\left(3\left(x+y\right)\right)^2\)
\(\Leftrightarrow\sqrt{\left(5x^2+2xy+2y^2\right)\left(2x^2+2xy+5y^2\right)}=x^2+7xy+y^2\)
\(\Rightarrow\left(5x^2+2xy+2y^2\right)\left(2x^2+2xy+5y^2\right)=\left(x^2+7xy+y^2\right)^2\)
\(\Leftrightarrow9\left(x-y\right)^2\left(x+y\right)^2=0\)\(\Leftrightarrow\left[{}\begin{matrix}x=y\\x=-y\end{matrix}\right.\)
\(\rightarrow\left(x;y\right)\in\left\{\left(0;0\right),\left(1;1\right)\right\}\)
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caau a) binh phuong len ra no x=y tuong tu
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c)
ĐK $y \geqslant 0$
Hệ đã cho tương đương với
$\left\{\begin{matrix} 2x^2+2xy+2x+6=0\\ (x+1)^2+3(y+1)+2xy=2\sqrt{y(x^2+2)} \end{matrix}\right.$
Trừ từng vế $2$ phương trình ta được
$x^2+2+2\sqrt{y(x^2+2)}-3y=0$
$\Leftrightarrow (\sqrt{x^2+2}-\sqrt{y})(\sqrt{x^2+2}+3\sqrt{y})=0$
$\Leftrightarrow x^2+2=y$
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Thực hiện các phép tính sau:
a).left(dfrac{2x+1}{2x-1}-dfrac{2x-1}{2x+1}right):dfrac{4x}{10x-5}
b). left(dfrac{1}{x^2+1}-dfrac{2-x}{x+1}right):left(dfrac{1}{x}+x-2right)
c). dfrac{1}{x-1}-dfrac{x^3-x}{x^2+1}.left(dfrac{1}{x^2-2x+1}+dfrac{1}{1-x^2}right)
d). left(dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+dfrac{y}{x^2+y^2}right):left(dfrac{1}{x-y}-dfrac{2xy}{x^3-x^2y+xy^2-y^3}right)
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Thực hiện các phép tính sau:
a).\(\left(\dfrac{2x+1}{2x-1}-\dfrac{2x-1}{2x+1}\right):\dfrac{4x}{10x-5}\)
b). \(\left(\dfrac{1}{x^2+1}-\dfrac{2-x}{x+1}\right):\left(\dfrac{1}{x}+x-2\right)\)
c). \(\dfrac{1}{x-1}-\dfrac{x^3-x}{x^2+1}.\left(\dfrac{1}{x^2-2x+1}+\dfrac{1}{1-x^2}\right)\)
d). \(\left(\dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+\dfrac{y}{x^2+y^2}\right):\left(\dfrac{1}{x-y}-\dfrac{2xy}{x^3-x^2y+xy^2-y^3}\right)\)
a) \(\left(\dfrac{2x+1}{2x-1}-\dfrac{2x-1}{2x+1}\right):\dfrac{4x}{10x-5}\)
\(=\left(\dfrac{\left(2x+1\right)\left(2x+1\right)}{2x^2-1}-\dfrac{\left(2x-1\right)\left(2x-1\right)}{2x^2-1}\right):\dfrac{4x}{10x-5}\)
\(=\left(\dfrac{\left(2x+1\right)^2-\left(2x-1\right)^2}{2x^2-1}\right):\dfrac{4x}{10x-5}\)
\(=\left(\dfrac{\left(2x+1-2x-1\right)\left(2x+1+2x-1\right)}{2x^2-1}\right):\dfrac{4x}{10x-5}\)
\(=\dfrac{4x}{2x^2-1}.\dfrac{5\left(2x-1\right)}{4x}\)
\(=\dfrac{5}{2x+1}\)
b) \(\left(\dfrac{1}{x^2+1}-\dfrac{2-x}{x+1}\right):\left(\dfrac{1}{x}+x-2\right)\)
\(=\left(\dfrac{1}{x^2+1}-\dfrac{x\left(2-x\right)}{x\left(x+1\right)}\right):\left(\dfrac{1}{x}+x-2\right)\)
\(=\left(\dfrac{1-2x+x^2}{x^2+1}\right):\left(\dfrac{1}{x}+x-2\right)\)
\(=\left(\dfrac{1-2x+x^2}{x^2+1}\right):\left(\dfrac{1}{x}+\dfrac{x^2}{x}-\dfrac{2x}{x}\right)\)
\(=\left(\dfrac{1-2x+x^2}{x^2+1}\right):\left(\dfrac{x^2-2x+1}{x}\right)\)
\(=\dfrac{\left(x-1\right)^2}{x^2+1}.\dfrac{x}{\left(x-1\right)^2}\)
\(=\dfrac{x}{x^2+1}\)
c) d) Tự làm đi mình làm biếng quass >.< ^^
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thực hiện phép tính:
a,\(\left(9x^2y^3-15x^4y^4\right):3x^2y-\left(2-3x^2y\right)y^2\)
b,\(\left(6x^2-xy\right):x+\left(2x^3y+3xy^2\right):xy-\left(2x-1\right)x\)
c,\(\left(x^2-xy\right):x-+\left(6x^2y^5-9x^3y^4+15x^4y^2\right):\dfrac{3}{2}x^2y^3\)
Tính :a) left(4x^2+2xy^2-xyright):xyb) left(y-xright)^2:left(x-yright)c) left(27x^3+y^3right):left(3x+yright)d) left(2x-3right)left(2x+3right)-left(4x-1right)left(x-1right)e) yleft(3y-1right)+3y-y^2f ) left(4y-1right)left(y+3right)g) left(x^2+2xyright):left(x+2yright)
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Tính :
a) \(\left(4x^2+2xy^2-xy\right):xy\)
b) \(\left(y-x\right)^2:\left(x-y\right)\)
c) \(\left(27x^3+y^3\right):\left(3x+y\right)\)
d) \(\left(2x-3\right)\left(2x+3\right)-\left(4x-1\right)\left(x-1\right)\)
e) \(y\left(3y-1\right)+3y-y^2\)
f ) \(\left(4y-1\right)\left(y+3\right)\)
g) \(\left(x^2+2xy\right):\left(x+2y\right)\)