a) 3x ^ 3 - 6x ^ 3 * y + 3xy
b) a ^ 2 - 4ab + 4b ^ 2 - 16
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Những câu hỏi liên quan
12 tháng 10 2021
Bài 2:
a: \(3x^2-3xy=3x\left(x-y\right)\)
b: \(x^2-4y^2=\left(x-2y\right)\left(x+2y\right)\)
c: \(3x-3y+xy-y^2=\left(x-y\right)\left(3+y\right)\)
d: \(x^2-y^2+2y-1=\left(x-y+1\right)\left(x+y-1\right)\)
12 tháng 10 2021
\(a,=10x-8y+3\\ b,=\left(x+y\right)^2:\left(x+y\right)=x+y\\ c,=\left(a+b\right)\left(3a-2c+d\right):\left(a+b\right)=3a-2c+d\\ d,=\left(x-1\right)^3:\left(x-1\right)^2=x-1\)
29 tháng 9 2018
\(x^2-2xy+y^2-a^2+4ab-4b^2\)
\(=\left(x-y\right)^2-\left(a-2b\right)^2\)
\(=\left(x-y-a+2b\right)\left(x-y+a-2b\right)\)
hk tốt
^^
20 tháng 6 2023
Sửa đề: B=-2x^2+xy+2y^2-3-5x+2y
a: A+B+C
=x^2-3xy-y^2+2x-3y+1-2x^2+xy+2y^2-3-5x+2y+C
=-x^2-2xy+y^2-3x-y-2+3x^2+7y^2-4xy-6x+4y+5
=2x^2+8y^2-6xy-9x+3y+3
b: 7A-B-C-9
=7A-9-(x^2+9y^2-3xy-11x+6y+2)
=7x^2-7y^2-21xy+14x-21y+7-x^2-9y^2+3xy-11x-6y-2-9
=6x^2-16y^2-18xy+3x-27y-4
15 tháng 8 2020
Bài 1 :
a) \(x^2+y^2\)
\(\Leftrightarrow x^2+2xy+y^2-2xy\)
\(\Leftrightarrow\left(x+y\right)^2-2xy=\left(-3\right)^2-2.\left(-28\right)=65\)
b) \(x^3+y^3\)
\(\Leftrightarrow\left(x+y\right)\left(x^2-xy+y^2\right)\)
\(\Leftrightarrow\left(x+y\right)\left(x^2+2xy+y^2-3xy\right)\)
\(\Leftrightarrow\left(x+y\right)\left[\left(x+y\right)^2-3xy\right]=\left(-3\right)\left[\left(-3\right)^2-3.\left(-28\right)\right]=-279\)
c) \(x^4+y^4\)
\(\Leftrightarrow\left(x+y\right)^4-4x^3y-4xy^3-6x^2y^2=\left(-3\right)^4-4\left(-28\right).65-6\left(-28\right)^2=2657\)
AD
29 tháng 7 2021
Bài 1 :
a) (3a+4b)3+(3a-4b)3-48a2b2
=27a3+108a2b+144ab2+64b3+27a3-108a2b+144ab2-64b3-48a2b2
=54a3+288ab2-48a2b2
=2a(27a2+144b2-24ab)
b) (5x+2y)(5x-2y)+(2x-y)3+(2x+y)3
=25x2-4y2+8x3-12x2y+6xy2-y3+8x3+12x2y+6xy2+y3
=16x3+25x2-y2+12xy2
=x2(16x+25)-y2(1-12x)
AD
29 tháng 7 2021
Bài 2 :
\(x^2-8x+7=0\)
\(\Leftrightarrow x^2-x-7x+7=0\)
\(\Leftrightarrow\left(x-7\right)\left(x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-1=0\\x-7=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=1\\x=7\end{cases}}\)
b)\(x^3-4x^2+3x=0\)
\(\Leftrightarrow\left(x^2-3\right)\left(x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x^2-3=0\\x-1=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\pm\sqrt{3}\\x=1\end{cases}}\)
c)Nếu đề đổi thành =1 thì có vẻ hợp lí hơn
d)\(\left(3x-1\right)^3-3\left(3x+2\right)^2+13=0\)
\(\Leftrightarrow27x^3-27x^2+9x-1-3\left(9x^2+12x+4\right)+13=0\)
\(\Leftrightarrow27x^3-27x^2+9x-1-27x^2-36x-12+13=0\)
\(\Leftrightarrow27x^3-54x^2-27x=0\)
\(\Leftrightarrow27x\left(x^2-2x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}27x=0\\x^2-2x-1=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\-\left(x^2+2x+1\right)=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\-\left(x+1\right)^2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-1\end{cases}}\)
#H
TT
1 tháng 11 2017
1
a,\(\left(2x+1\right)\left(3x+1\right)-\left(6x-1\right)\left(x+1\right)\)
=\(6x^2+2x+3x+1-\left(6x^2+6x-x-1\right)\)
\(=6x^2+5x+1-6x^2-6x+x+1\)
\(=2\)
c,\(\left(a+1\right)\left(a^2-a+1\right)+\left(a+1\right)\left(a-1\right)\)
\(=\left(a^3+1\right)+\left(a^2-1\right)\)
\(=a^3+1+a^2-1\)
\(=a^3+a^2\)
2,
a,\(4ab+a^2-3a-12b\)
\(=\left(4ab-12b\right)+\left(a^2-3a\right)\)
\(=4b\left(a-3\right)+a\left(a-3\right)\)
\(=\left(4b+a\right)\left(a-3\right)\)
b,\(x^3+3x^2+3x+1-27y^3\)
\(=\left(x+1\right)^3-\left(3y\right)^3\)
\(=\left(x+1-3y\right)\left[\left(x+1\right)^2+\left(x+1\right).3y+\left(3y\right)^2\right]\)
\(=\left(x+1-3y\right)\left(x^2+2x+1+3xy+3y+9y^2\right)\)
4
a,\(2004^2-16\)
\(=2004^2-4^2\)
\(=\left(2004-4\right)\left(2004+4\right)\)
\(=2000.2008\)
\(=4016000\)
b,\(892^2+892.216+108^2\)
\(=\left(892+108\right)^2\)
\(=1000^2=1000000\)
c,\(10,2.9,8-9,8.0,2+10,2^2-10,2.0,2\)
\(=9,8\left(10,2-0,2\right)+10,2\left(10,2-0,2\right)\)
\(=9,8.10+10,2.10\)
\(=98+102\)
\(=200\)
d,\(36^2+26^2-52.36\)
=\(\left(36-26\right)^2\)
\(=10^2=100\)
AN
1 tháng 11 2017
3)\(A=-x^2+2x-3\)
\(\Leftrightarrow A=-x^2+2x-1-2\)
\(\Leftrightarrow A=-\left(x^2-2x+1\right)-2\)
\(\Leftrightarrow A=-\left(x-1\right)^2-2\)
Vậy GTLN của A=-2 khi x=1
13 tháng 10 2017
a) x3 - 2x2 - 9x + 18
= x2( x - 2) - 9( x - 2)
= ( x2 - 32).( x -2)
= ( x -3).( x+3).( x-2)
b) x2 - a2 - 4ab - 4b2
= -[ a2 + 2.2ab + (2b)2 - x2]
= -[ ( a + 2b)2 - x2]
= -( a + 2b - x).( a +2b +x)
c) x2 - x - 2
= x2 - 2x + x -2
= x( x -2) + ( x-2)
= ( x+ 1).( x-2)
d) x2 + x -6
= x2 - 22 + x -2
= ( x -2).( x +2) + ( x -2)
= ( x -2).( x+3)
e) x3 - 3x2 - 4x + 12
= x2( x - 3) - 4( x - 3)
= ( x2 - 22).( x -3)
= ( x-2).(x+2).(x-3)
4 tháng 2 2022
Câu 1:
a: \(=6x^2+5x+1-6x^2-6x+x+1=2\)
b: \(=a^3+1-a^2+1=a^3-a^2+2\)
\(3x^3-6x^3y+3xy=3x\left(x^2-2x^2y+y\right)\)
\(a^2-4ab+4b^2-16=\left(a-2b\right)^2-4^2=\left(a-2b-4\right)\left(a-2b+4\right)\)