\(\left(5-x\right)^5:\left(x-5\right)^4\)
Những câu hỏi liên quan
1)4left(x-5right)-3left(x+7right)-192)7left(x-3right)-5left(3-xright)11x-53)4left(2-xright)+4left(x-3right)144)-5left(2-xright)+4left(x-3right)10x-155)7left(x-9right)-5left(6-xright)-5+11x6)-7left(3x-5right)+2left(7x-14right)287)4left(x-5right)-3left(x+7right)5.left(-4right)
Đọc tiếp
1)\(4\left(x-5\right)-3\left(x+7\right)=-19\)
2)\(7\left(x-3\right)-5\left(3-x\right)=11x-5\)
3)\(4\left(2-x\right)+4\left(x-3\right)=14\)
4)\(-5\left(2-x\right)+4\left(x-3\right)=10x-15\)
5)\(7\left(x-9\right)-5\left(6-x\right)=-5+11x\)
6)\(-7\left(3x-5\right)+2\left(7x-14\right)=28\)
7)\(4\left(x-5\right)-3\left(x+7\right)=5.\left(-4\right)\)
a ) Ta có : 4(x - 5) - 3(x + 7) = -19
<=> 4x - 20 - 3x - 21 = -19
=> x - 41 = -19
=> x = -19 + 41
=> x = 22
b) Ta có " 7(x - 3) - 5(3 - x) = 11x - 5
<=> 7x - 21 - 15 + 5x = 11x - 5
<=> 12x - 36 = 11x - 5
=> 12x - 11x = -5 + 36
=> x = 31
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Làm tính chia:
a) \(5^3:\left(-5\right)^2\)
b) \(\left(\dfrac{3}{4}\right)^5:\left(\dfrac{3}{4}\right)^3\)
c) \(\left(-12\right)^3-8^3\)
d) \(x^{10}:\left(-x\right)^8\)
e) \(\left(-x\right)^5:\left(-x\right)^3\)
f) \(\left(-y\right)^5:\left(-y\right)^4.\)
\(a,=5^3:5^2=5\\ b,=\left(\dfrac{3}{4}\right)^{5-3}=\left(\dfrac{3}{4}\right)^2=\dfrac{9}{16}\\ c,=1728-512=1216\\ d,=x^{10}:x^8=x^2\\ e,=\left(-x\right)^{5-3}=\left(-x\right)^2=x^2\\ f,=\left(-y\right)^{5-4}=-y\)
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Giải phương trình \(\dfrac{3\left(x-\sqrt{3}\right)\left(x-\sqrt{5}\right)}{\left(1-\sqrt{3}\right)\left(1-\sqrt{5}\right)}+\dfrac{4\left(x-1\right)\left(x-\sqrt{5}\right)}{\left(\sqrt{3}-1\right)\left(\sqrt{3}-\sqrt{5}\right)}+\dfrac{5\left(x-1\right)\left(x-\sqrt{3}\right)}{\left(\sqrt{5}-1\right)\left(\sqrt{5}-\sqrt{3}\right)}=3x-2\)
1.tìm x
a) left(8-5xright)left(x+2right)+4left(x-2right)left(x+1right)+2left(x-2right)left(x+2right)
b) 4left(x-1right)left(x+5right)-left(x+2right)left(x+5right)3left(x-1right)left(x+2right)
2. CMR
a) left(x-yright)left(x^4+x^3y+x^2y^2+xy^3+y^4right)x^5-y^5
b)left(x+yright)left(x^4-x^3y+x^2y^2-xy^3+y^4right)x^5+y^5
c)left(x+aright)left(x+bright)x^2+left(a+bright)x+ab
giúp mik nha
chiều nay nộp r
Đọc tiếp
1.tìm x
a) \(\left(8-5x\right)\left(x+2\right)+4\left(x-2\right)\left(x+1\right)+2\left(x-2\right)\left(x+2\right)\)
b) \(4\left(x-1\right)\left(x+5\right)-\left(x+2\right)\left(x+5\right)=3\left(x-1\right)\left(x+2\right)\)
2. CMR
a) \(\left(x-y\right)\left(x^4+x^3y+x^2y^2+xy^3+y^4\right)=x^5-y^5\)
b)\(\left(x+y\right)\left(x^4-x^3y+x^2y^2-xy^3+y^4\right)=x^5+y^5\)
c)\(\left(x+a\right)\left(x+b\right)=x^2+\left(a+b\right)x+ab\)
giúp mik nha
chiều nay nộp r
2. CMR:
a. \(\left(x-y\right)\left(x^4+x^3y+x^2y^2+xy^3+y^4\right)=x^5-y^5\)
Ta có: VT=\(\left(x-y\right)\left(x^4+x^3y+x^2y^2+xy^3+y^4\right)=x^5+x^4y+x^3y^2+x^2y^3+xy^4-x^4y-x^3y^2-x^2y^3-xy^4-y^5=x^5-y^5=VP\)=> đpcm.
b. \(\left(x+y\right)\left(x^4-x^3y+x^2y^2-xy^3+y^4\right)=x^5+y^5\)
Ta có: VT=\(\left(x+y\right)\left(x^4-x^3y+x^2y^2-xy^3+y^4\right)=x^5-x^4y+x^3y^2-x^2y^3+xy^4+x^4y-x^3y^2+x^2y^3-xy^4+y^5=x^5+y^5=VP\)
=> đpcm.
c. \(\left(x+a\right)\left(x+b\right)=x^2+\left(a+b\right)x+ab\)
\(\Leftrightarrow x^2+bx+ax+ab=x^2+ax+bx+ab\) (đúng)
=> đpcm.
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1.
b. \(4\left(x-1\right)\left(x+5\right)-\left(x+2\right)\left(x+5\right)=3\left(x-1\right)\left(x+2\right)\)
\(\Leftrightarrow4\left(x^2+5x-x-5\right)-\left(x^2+5x+2x+10\right)=3\left(x^2+2x-x-2\right)\)
\(\Leftrightarrow4x^2+20x-4x-20-x^2-5x-2x-10=3x^2+6x-3x-6\)
\(\Leftrightarrow4x^2+20x-4x-x^2-5x-2x-3x^2-6x+3x=20+10-6\)
\(\Leftrightarrow6x=24\)
\(\Leftrightarrow x=4\)
Vậy ....
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\(a\text{)}.\: \left(8-5x\right)\left(x+2\right)+4\left(x-2\right)\left(x+1\right)+2\left(x-2\right)\left(x+2\right)=0\\ \Leftrightarrow8x-5x^2+16-10x+4x^2-4x-8+2x^2-8=0\\ \Leftrightarrow x^2-6x=0\Leftrightarrow x\left(x-6\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=6\end{matrix}\right.\)
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1)Tìm x, biết :
4.left[3x-1right]+left[xright]-2.left[x-5right]+7.left[x-3right]12
left[2dfrac{1}{5}-xright]+left[x-dfrac{1}{5}right]+8dfrac{1}{5}1,2
3.left[x+4right]-left[2.x+1right]-5.left[x-3right]+left[x-9right]5
2left[x+3dfrac{1}{2}right]+left[xright]-3dfrac{1}{2}left[2dfrac{1}{5}-xright]
Đọc tiếp
1)Tìm x, biết :
\(4.\left[3x-1\right]+\left[x\right]-2.\left[x-5\right]+7.\left[x-3\right]=12\)
\(\left[2\dfrac{1}{5}-x\right]+\left[x-\dfrac{1}{5}\right]+8\dfrac{1}{5}=1,2\)
\(3.\left[x+4\right]-\left[2.x+1\right]-5.\left[x-3\right]+\left[x-9\right]=5\)
\(2\left[x+3\dfrac{1}{2}\right]+\left[x\right]-3\dfrac{1}{2}=\left[2\dfrac{1}{5}-x\right]\)
Tìm x:
1, \(\left(x-5\right)\cdot\left(x+5\right)-\left(x+3\right)^2=2x-3\)
2,\(\left(2x+3\right)^2+\left(x-1\right)\cdot\left(x+1\right)=5\cdot\left(x+2\right)^2\)
3, \(\left(x-4\right)^3-\left(x-5\right)\cdot\left(x^2+5x+25\right)=\left(x+2\right)\cdot\left(x^2-2x+4\right)-\left(x+4\right)^3\)
1.\(\left(x-5\right).\left(x+5\right)-\left(x+3\right)^2=2x-3\)
\(\Leftrightarrow x^2-25-\left(x^2+6x+9\right)=2x-3\)
\(\Leftrightarrow x^2-25-x^2-6x-9=2x-3\)
\(\Leftrightarrow x^2-25-x^2-6x-9-2x+3=0\)
\(\Leftrightarrow-8x-31=0\)
\(\Leftrightarrow x=\dfrac{-31}{8}\)
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\(\left(x-4\right)^3-\left(x-5\right)\left(x^2+5x+25\right)=\left(x+2\right)\left(x^2-2x+4\right)-\left(x+4\right)^3\)
\(\Leftrightarrow\left(x-4\right)^3-\left(x^3-5^3\right)=\left(x^3+2^3\right)-\left(x+4\right)^3\)
\(\Leftrightarrow\left(x-4\right)^3-x^3+5^3=x^3+2^3-\left(x+4\right)^3\)
\(\Leftrightarrow\left(x^3-12x^2+48x-64\right)-x^3+5^3=x^3+2^3-\left(x^3+12x^2+48x+64\right)\)
\(\Leftrightarrow x^3-12x^2+48x-64-x^3+5^3=x^3+2^3-x^3-12x^2-48x-64\)
\(\Leftrightarrow-12x^2+48x-64+5^3=2^3-12x^2-48x-64\)
\(\Leftrightarrow-12x^2+48x-61=-12x^2-48x-56\)
\(\Leftrightarrow96x=-117\)
\(\Leftrightarrow x=\dfrac{-117}{96}=\dfrac{-39}{32}\)
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2. \(\left(2x+3\right)^2+\left(x-1\right)\left(x+1\right)=5\left(x+2\right)^2\)
\(\Leftrightarrow4x^2+12x+9+x^2-1=5\left(x^2+4x+4\right)\)
\(\Leftrightarrow4x^2+12x+9+x^2-1=5x^2+20x+20\)
\(\Leftrightarrow4x^2+x^2-5x^2+12x-20x=20-9+1\)
\(\Leftrightarrow-8x=12\)
\(\Leftrightarrow x=\dfrac{-12}{8}=\dfrac{-3}{2}\)
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BT6: Thu gọn về hàng đẳng thức
\(3,\left(x+3\right)^2+\left(x-2\right)^2-2\left(x+3\right)\left(x-2\right)\)
\(4,\left(3x-5\right)^2-2\left(3x-5\right)\left(3x+5\right)+\left(3x+5\right)^2\)
3) \(\left(x+3\right)^2+\left(x-2\right)^2-2\left(x+3\right)\left(x-2\right)\)
\(=\left(x+3\right)^2-2\left(x+3\right)\left(x-2\right)+\left(x-2\right)^2\)
\(=\left[\left(x+3\right)-\left(x-2\right)\right]^2\)
\(=\left(x+3-x+2\right)^2\)
\(=5^2=25\)
4) \(\left(3x-5\right)^2-2\left(3x-5\right)\left(3x+5\right)+\left(3x+5\right)^2\)
\(=\left[\left(3x-5\right)-\left(3x+5\right)\right]^2\)
\(=\left(3x-5-3x-5\right)^2\)
\(=\left(-10\right)^2\)
\(=100\)
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tìm x biết :
\(\left|x-1\right|+2.\left|x-2\right|+3.\left|x-3\right|+4.\left|x-4\right|+5.\left|x-5\right|+20x=0\)
\(\left|x-1\right|+2\left|x-2\right|+3\left|x-3\right|+4\left|x-4\right|+5\left|x-5\right|+20x=0\left(1\right)\)
TH1: x<1
(1) trở thành 1-x+2(2-x)+3(3-x)+4(4-x)+5(5-x)+20x=0
=>\(1-x+4-2x+9-3x+16-4x+25-5x+20x=0\)
=>\(5x+55=0\)
=>x=-11(nhận)
TH2: 1<=x<2
Phương trình (1) sẽ trở thành:
\(x-1+2\left(2-x\right)+3\left(3-x\right)+4\left(4-x\right)+5\left(5-x\right)+20x=0\)
=>\(x-1+4-2x+9-3x+16-4x+25-5x+20x=0\)
=>\(7x+53=0\)
=>\(x=-\dfrac{53}{7}\left(loại\right)\)
TH3: 2<=x<3
Phương trình (1) sẽ trở thành:
\(x-1+2\left(x-2\right)+3\left(3-x\right)+4\left(4-x\right)+5\left(5-x\right)+20x=0\)
=>\(x-1+2x-4+9-3x+16-4x+25-5x+20x=0\)
=>\(11x+45=0\)
=>\(x=-\dfrac{45}{11}\left(loại\right)\)
TH4: 3<=x<4
Phương trình (1) sẽ trở thành:
\(x-1+2\left(x-2\right)+3\left(x-3\right)+4\left(4-x\right)+5\left(5-x\right)+20x=0\)
=>\(x-1+2x-4+3x-9+16-4x+25-5x+20x=0\)
=>\(-3x+27=0\)
=>x=9(loại)
TH5: 4<=x<5
Phương trình (1) sẽ trở thành:
\(\left(x-1\right)+2\left(x-2\right)+3\left(x-3\right)+4\left(x-4\right)+5\left(5-x\right)+20x=0\)
=>\(x-1+2x-4+3x-9+4x-16+25-5x+20x=0\)
=>\(25x-5=0\)
=>x=1/5(loại)
TH6: x>=5
Phương trình (1) sẽ trở thành:
\(\left(x-1\right)+2\left(x-2\right)+3\left(x-3\right)+4\left(x-4\right)+5\left(x-5\right)+20x=0\)
=>\(x-1+2x-4+3x-9+4x-16+5x-25+20x=0\)
=>35x-55=0
=>x=55/35(loại)
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Giải phương trình
\(\frac{3\left(x-\sqrt{3}\right)\left(x-\sqrt{5}\right)}{\left(1-\sqrt{3}\right)\left(1-\sqrt{5}\right)}+\frac{4\left(x-1\right)\left(x-\sqrt{5}\right)}{\left(\sqrt{3}-1\right)\left(\sqrt{3}-\sqrt{5}\right)}+\frac{5\left(x-1\right)\left(x+\sqrt{3}\right)}{\left(\sqrt{5}-1\right)\left(\sqrt{5}-\sqrt{3}\right)}=3x-2\)
Bài 4:Rút gọn biểu thức a) 2xleft(x-5right)-left(x-2right)^2-left(x+3right).left(x-3right)b) left(x+1right)^2+3left(x-5right).left(x+5right)-left(2x-1right)^2c) 2xleft(x-7right)-left(x+3right)left(x-2right)-left(x+4right)left(x-4right)d) left(x+3right)left(x-3right)-left(x+5right).left(x-1right)-left(x-4right)^2
Đọc tiếp
Bài 4:Rút gọn biểu thức
a) \(2x\left(x-5\right)-\left(x-2\right)^2-\left(x+3\right).\left(x-3\right)\)
b) \(\left(x+1\right)^2+3\left(x-5\right).\left(x+5\right)-\left(2x-1\right)^2\)
c) \(2x\left(x-7\right)-\left(x+3\right)\left(x-2\right)-\left(x+4\right)\left(x-4\right)\)
d) \(\left(x+3\right)\left(x-3\right)-\left(x+5\right).\left(x-1\right)-\left(x-4\right)^2\)
a. \(2x\left(x-5\right)-\left(x-2\right)^2-\left(x+3\right)\left(x-3\right)\)
\(=2x^2-10x-x^2+4x-4-x^2+9\)
\(=-6x+5\)
b. \(\left(x+1\right)^2+3\left(x-5\right)\left(x+5\right)-\left(2x-1\right)^2\)
\(=x^2+2x+1+3x^2-75-4x^2+4x-1\)
\(=6x-75\)
c. \(2x\left(x-7\right)-\left(x+3\right)\left(x-2\right)-\left(x+4\right)\left(x-4\right)\)
\(=2x^2-14x-x^2-x+6-x^2+16\)
\(=-15x+22\)
d. \(\left(x+3\right)\left(x-3\right)-\left(x+5\right)\left(x-1\right)-\left(x-4\right)^2\)
\(=x^2-9-x^2-4x+5-x^2+8x-16\)
\(=-x^2+4x-20\)
Bài làm:
a) \(2x\left(x-5\right)-\left(x-2\right)^2-\left(x+3\right)\left(x-3\right)\)
\(=2x^2-10x-x^2+4x-4-x^2+9\)
\(=-6x+5\)
b) \(\left(x+1\right)^2+3\left(x-5\right)\left(x+5\right)-\left(2x-1\right)^2\)
\(=x^2+2x+1+3x^2-75-4x^2+4x-1\)
\(=6x-75\)
c) \(2x\left(x-7\right)-\left(x+3\right)\left(x-2\right)-\left(x+4\right)\left(x-4\right)\)
\(=2x^2-14x-x^2-x+6-x^2+16\)
\(=-15x+22\)
d) \(\left(x+3\right)\left(x-3\right)-\left(x+5\right)\left(x-1\right)-\left(x-4\right)^2\)
\(=x^2-9-x^2-4x+5-x^2+8x-16\)
\(=-x^2-4x-20\)
đầy đủ từng bước nhé
\(a,2x\left(x-5\right)-\left(x-2\right)^2-\left(x+3\right)\left(x-3\right)\)
\(=2x^2-10x-\left(x^2-4x+4\right)-\left(x^2-9\right)\)
\(=2x^2-10x-x^2+4x-4-x^2+9\)
\(=\left(2x^2-x^2-x^2\right)+\left(4x-10x\right)+\left(9-4\right)\)
\(=0-6x+5=5-6x\)
\(b,\left(x+1\right)^2+3\left(x-5\right)\left(x+5\right)-\left(2x-1\right)^2\)
\(=\left(x^2+2x+1\right)+3\left(x^2-25\right)-\left(4x^2-4x+1\right)\)
\(=x^2+2x+1+3x^2-75-4x^2+4x-1\)
\(=\left(x^2+3x^2-4x^2\right)+\left(2x+4x\right)+\left(1-1-75\right)\)\(=6x-75\)
\(c,2x\left(x-7\right)-\left(x+3\right)\left(x-2\right)-\left(x+4\right)\left(x-4\right)\)
\(=2x^2-14x-\left(x+2\right)\left(x-2\right)-x+2-\left(x+4\right)\left(x-4\right)\)
\(=2x^2-14x-x^2+4-x+2-x^2+16\)
\(=\left(2x^2-x^2-x^2\right)+\left(-14x-x\right)+\left(16+2+4\right)\)
\(=0-15x+22=22-15x\)
\(d,\left(x+3\right)\left(x-3\right)-\left(x+5\right)\left(x-1\right)-\left(x-4\right)^2\)
\(=\left(x+3\right)\left(x-3\right)-\left(x+1\right)\left(x-1\right)-4\left(x-1\right)-\left(x-4\right)^2\)
\(=x^2-9-x^2+1-4x+4-\left(x^2-8x+16\right)\)
\(=\left(x^2-x^2\right)-4x+\left(4+1-9\right)-x^2+8x-16\)
\(=-4x-4-x^2+8x-16=-x^2+\left(8x-4x\right)-\left(16+4\right)\)
\(=-x^2+4x-20\)
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