4x^2+64y^2
Tính
\(4x^2-12x-64y^2+9\)
ban con choi bangbang ko cho minh muon nick
Viết các đa thức sau thành tích
a, 4x^2 - 25y^2
b, 8x^3 + 27
c, 125x^3 - 64y^3
Giúp em với cảm ơn mọi người
`a, 4x^2 - 25y^2 = (2x-5y)(2x+5y)`.
`b, 8x^3 +27 = (2x+3)(4x^2 - 6x + 9)`.
`c, 125x^3 - 64y^3 = (5x)^3 - (4y)^3 = (5x-4y)(25x^2 + 20xy + 16y^2)`.
\(a,\\ 4x^2-25y^2=\left(2x\right)^2-\left(5y\right)^2=\left(2x-5y\right)\left(2x+5y\right)\\ b,\\ 8x^3+27=\left(2x\right)^3+3^3=\left(2x+3\right)\left(4x^2+6x+9\right)\\ c,\\ 125x^3-64y^3=\left(5x\right)^3-\left(4y\right)^3=\left(5x-4y\right)\left(25x^2+20xy+16y^2\right)\)
Phân tích các đa tử sau thành nhân tử
a. 15x^2 – 5x^3
b. 8x^3 +4x^2y – y^3 – 2xy^2
c. x^8 + 64y^4
a: \(15x^2-5x^3=5x^2\left(3-x\right)\)
b: \(8x^3-y^3+4x^2y-2xy^2\)
\(=\left(2x-y\right)\left(4x^2+2xy+y^2\right)+2xy\left(2x-y\right)\)
\(=\left(2x-y\right)\left(4x^2+4xy+y^2\right)\)
\(=\left(2x-y\right)\left(2x+y\right)^2\)
c: Ta có: \(x^8+64y^4\)
\(=x^8+16x^4y^2+64y^4-16x^4y^2\)
\(=\left(x^4+8y^2\right)^2-\left(4x^2y\right)^2\)
\(=\left(x^2-4x^2y+8y^2\right)\left(x^2+4x^2y+8y^2\right)\)
Phân tích đa thức thành nhân tử : A= ( x^2 - y^2 + 2x) + 1 B=x^4 + 64y^4 C= ( x^2 + x)^2 + 2.(x^2 + x)-3 D= (x^2 - 4x)^2 +7(x^2- 4x)+12
A = (x^2 - y^2 + 2x) + 1 = (x^2 + 2x + 1)-y^2 = (x+1)^2 - y^2 =
(x+1-y)(x+1+y)
B = x^4 - 64y^4 = (x^2)^2 - (8y^2)^2 = (x^2 - 8y^2 ) (x^2 + 8y^2 )
C = (x^2 + x)^2 + 2(x^2 + x) - 3
= (x^2 + x)^2 + 2(x^2 + x) + 1 - 2^2
= (x^2 + x + 1) - 2^2 = (x^2 + x + 1 - 2)(x^2 + x + 1 + 2 )
= (x^2 + x - 1)(x^2 + x + 3)
D = (x^2 - 4x)^2 + 7(x^2 - 4x) + 12
= (x^2 - 4x)^2 + 2(x^2 - 4x). 7/2 + 49/4 - 1/4
= (x^2 - 4x + 7/2)^2 - 1/4
= (x^2 - 4x + 7/2 - 1/4)(x^2 - 4x + 7/2 + 1/4)
= (x^2 - 4x + 13/4)(x^2 - 4x +15/4)
D = (x^2 - 4x)^2 + 7(x^2 - 4x) + 12
= (x^2 - 4x)^2 + 2(x^2 - 4x).7/2 + 49/4 - 1/4
= (x^2 - 4x + 7/2)^2 - 1/4
= (x^2 - 4x + 7/2 - 1/2)(x^2 - 4x + 7/2 + 1/2)
= (x^2 - 4x + 3)(x^2 - 4x + 4)
viết dưới dạng tichj theo hàng đẳng thưc
a ,8x^3 - 64y^3
9x^2-30xy+25y^2
4x^2+16x+7
-5+18y-9y^2
\(8x^3-64y^3=\left(2x\right)^3-\left(4y\right)^3=\left(2x-4y\right)\left(4x^2+8xy+16y^2\right)\)
\(9x^2-30xy+25y^2=\left(3x\right)^2-2\cdot3x\cdot5y+\left(5y\right)^2=\left(3x-5y\right)^2\)
\(4x^2+16x+7=\left(2x^2\right)+2\cdot2x\cdot4+4^2-9=\left(2x+4\right)^2-3^2=\left(2x+1\right)\left(2x+7\right)\)
\(-5+18y-9y^2=-\left[\left(3y\right)^2-2\cdot3y\cdot3+3^2-4\right]=-\left[\left(3y-3\right)^2-2^2\right]=-\left(3y-5\right)\left(3y-1\right)\)
bài 3 ; áp dụng hằng đẳng thức để thực hiện phép chia
a, ( 4x mũ 2 + 12xy + 9y mũ 2 ) : ( 2x + 3y )
d, ( x mũ 2 + 6xy + 9y mũ 2 ) : ( x + 3y )
e, ( 64y mũ 3 - 27 ) : ( 4y - 3 )
a: \(\left(4x^2+12xy+9y^2\right):\left(2x+3y\right)=\left(2x+3y\right)^2:\left(2x+3y\right)=2x+3y\)
d: \(\left(x^2+6xy+9y^2\right):\left(x+3y\right)=\left(x+3y\right)^2:\left(x+3y\right)=x+3y\)
e: \(\dfrac{64y^3-27}{4y-3}=\dfrac{\left(4y-3\right)\left(16y^2+12y+9\right)}{4y-3}=16y^2+12y+9\)
a, \(4x^2+12xy+9y^2=\left(2x+3y\right)^2\)
\(\Rightarrow\left(4x^2+12xy+9y^2\right):\left(2x+3y\right)\)
\(=\left(2x+3y\right)^2:\left(2x+3y\right)\\ =2x+3y\)
b,\(x^2+6xy+9y^2=\left(x+3y\right)^2\)
\(\Rightarrow\left(x^2+6xy+9y^2\right):\left(x+3y\right)\\ =\left(x+3y\right)^2:\left(x+3y\right)\\ =x+3y\)
c, \(64y^3-27=\left(4y-3\right)\left(16y^2+12y+9\right)\)
\(\Rightarrow\left(64x^3-27\right):\left(4y-3\right)\\ =\left[\left(4y-3\right)\left(16x^2+12x+9\right)\right]:\left(4y-3\right)\\ =16x^2+12x+9\)
Viết các đa thức sau thành tích:
1) 8z^3+27.
2) 9/25x^4-1/4
3) x^32-1
4) 4x^2+4x+1
5) x^2-20x+100
6) y^4-14y^2+49
7) 125x^3-64y^3
1) \(=\left(2z+3\right)\left(4z^2-6z+9\right)\)
2) \(=\left(\frac{3x^2}{5}-\frac{1}{2}\right)\left(\frac{3x^2}{5}+\frac{1}{2}\right)\)
3) \(=\left(x-1\right)\left(x+1\right)\left(x^2+1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\)
4) \(=\left(2x+1\right)^2\)
5) \(=\left(x-10\right)^2\)
6) \(=\left(y^2-7\right)^2\)
7) \(=\left(5x-4y\right)\left(25x^2+20xy+16y^2\right)\)
Cảm ơn bạn nhiều nha 😁😁😁😁
phân tích đa thức thành nhân tử
a, x4+64y4
b, 4x4+y4
c,(x+1).(x+2).(x+3).(x+4)-3
d, x4+x2+1
a/ \(=64y^4+32xy^3+8y^2x^2-32xy^3-16x^2y^2-4x^3y+8x^2y^2+4x^3y+x^4\)
\(=8y^2\left(8y^2+4xy+x^2\right)-4xy\left(8y^2+4xy+x^2\right)+x^2\left(8y^2+4xy+x^2\right)\)
\(=\left(8y^2-4xy+x^2\right)\left(8y^2+4xy+x^2\right)\)
b/ \(=y^4+2xy^3+2x^2y^2-2xy^3-4x^2y^2-4x^3y+2x^2y^2+4x^3y+4x^4\)
\(=y^2\left(y^2+2xy+2x^2\right)-2xy\left(y^2+2xy+2x^2\right)+2x^2\left(y^2+2xy+2x^2\right)\)
\(=\left(y^2-2xy+2x^2\right)\left(y^2+2xy+2x^2\right)\)
c/ \(=x^4+5x^3+7x^2+5x^3+25x^2+35x+3x^2+15x+21\)
\(=x^2\left(x^2+5x+7\right)+5x\left(x^2+5x+7\right)+3\left(x^2+5x+7\right)\)
\(=\left(x^2+5x+3\right)\left(x^2+5x+7\right)\)
d/ \(=x^4+x^3+x^2-x^3-x^2-x+x^2+x+1\)
\(=x^2\left(x^2+x+1\right)-x\left(x^2+x+1\right)+\left(x^2+x+1\right)\)
\(=\left(x^2-x+1\right)\left(x^2+x+1\right)\)
x^2+6x+9
10x-25-x^2
8x^3-1/8
1/25x^2-64y^2
1) \(x^2+6x+9\)
\(=\left(x+3\right)^2\)
2) \(10x-25-x^2\)
\(=-25+10x-x^2\)
\(=-\left(5-x\right)^2\)
3) \(8x^3-\dfrac{1}{8}\)
\(=\left(2x\right)^3-\left(\dfrac{1}{2}\right)^3\)
\(=\left(2x-\dfrac{1}{2}\right)\left(4x^2+x+\dfrac{1}{4}\right)\)
4) \(\dfrac{1}{25}x^2-64y^2\)
\(=\left(\dfrac{1}{5}x\right)^2-\left(8y\right)^2\)
\(=\left(\dfrac{1}{5}x+8y\right)\left(\dfrac{1}{5}x-8y\right)\)
\(x^2+6x+9=\left(x+3\right)^2\)
\(10x-25-x^2=-\left(x-5\right)^2\)
\(8x^3-\dfrac{1}{8}=\left(2x-\dfrac{1}{2}\right)\left(4x^2+x+\dfrac{1}{4}\right)\)
Bài 1: Phân tích các đa thức sau thành nhân tử. 7) (xy + 4) mũ 2 – (2x + 2y) mũ 2 8) 81x mũ 2 – 64y mũ 2 9) (a mũ 2 + b mũ 2 + 5) mũ 2 - 4 (ab + 2) mũ 2 10) (x – 1) mũ 2 – (x + 1) mũ 2 11) 8x mũ 3 - 1/8 12) 1/25x mũ 2 - 64y mũ 2 13) x mũ 3 + 1/27