phân tích a) 16x^2y-4xy^2-4x^3+x^2y
b) x^2-7x+6
CÂU 3: PHÂN TÍCH ĐA THỨC THÀNH NHÂN TỬ:
A) 3x^3-6x^2+3x
B) 16x^2y-4xy^2-4x^3
C) x^2+4x+4-9y^2
D) x^2-5x-6
\(a,3x^3-6x^2+3x\)
\(=3x\left(x^2-2x+1\right)\)
\(=3x\left(x-1\right)^2\)
\(b,16x^2y-4xy^2-4x^3\)
\(=-4x\left(x^2-4xy+4y^2-3y^2\right)\)
\(=-4x\left(x-2y+y\sqrt{3}\right)\left(x-2y-y\sqrt{3}\right)\)
Phân tích thành nhân tử
\(16x^2y-4xy^2-4x^3+x^2y\)
=(16x2y+x2y)-4xy2-4x3
=17x2-4xy2-4x3
\(giải:\)
\(16x^2y-4xy^2-4x^3+x^2y\)
\(=\left(16x^2y-4xy^2\right)-\left(4x^3-x^2y\right)\)
\(=4xy\left(4x-y\right)-x^2\left(4x-y\right)\)
\(=\left(4x-y\right)\left(4xy-x^2\right)\)
\(=\left(4x-y\right)\left(\sqrt{4xy}-x\right)\left(\sqrt{4xy}+x\right)\)
\(=\left(4x-y\right)\left(2\sqrt{xy}-x\right)\left(2\sqrt{xy}+x\right)\)
Hãy phân tích các đa thức sau thành nhân tử:
a) 4xy^2 – 2x^2y
b) x^3 + 5x – 4x^2 – 20
c) x^2 (x – y) + 25(y – x)
\(a,=2xy\left(2y-x\right)\\ b,=x^2\left(x-4\right)+5\left(x-4\right)=\left(x^2+5\right)\left(x-4\right)\\ c,=\left(x-y\right)\left(x^2-25\right)=\left(x-y\right)\left(x-5\right)\left(x+5\right)\)
1/A=-x^2+4y^2-2xy+4x-10y+2020
2/B=-7x^2-y^2+4xy+16x-2y+17
phân tích đa thức thành nhân tử
a) 3x^2-7x+10
b) X^3-4x^2y +4xy^2-y^3
b) \(x^3-4x^2y+4xy^2-y^3\)
\(=x^3-3x^2y-x^2y+3xy^2+xy^2-y^3\)
\(=\left(x^3-3x^2y+3xy^2-y^3\right)-\left(x^2y-xy^2\right)\)
\(=\left(x-y\right)^3-xy\left(x-y\right)\)
\(=\left(x-y\right)\left[\left(x-y\right)^2-xy\right]\)
\(=\left(x-y\right)\left(x^2-2xy+y^2-xy\right)\)
\(=\left(x-y\right)\left(x^2-3xy+y^2\right)\)
1 . (3x-5)^2 - (x-1)^2
2 . x^2 - 7x + 10
3 . 3x^2 + 7x + 10
4 . 2x^2 - 16x - 8y^2 + 32
5. 3x^2 + xy^2 - x - y
6 . 2x^2 -2y^2 + 3x - 3y
7 . 36 - 4x^2 - 4xy - y^2
Giai hộ mình nha
bài 4 phân tích
3x^2-30x+75
xy -x^2-x^2-x
x^2-7x-8
4x^3 +8x^2y+4xy^2-16x
xy+xz -2y-2z
x^2+6x+9-y^3
a)\(=3\left(x-5\right)^2\)
b)\(=x\left(y-2x-1\right)\)
c)\(=\left(x+1\right)\left(x-8\right)\)
d)\(=4x\left(x+y+2\right)\left(x+y-2\right)\)
e)\(=\left(y+z\right)\left(x-2\right)\)
g)\(=\left(x+3+y\right)\left(x+3-y\right)\)
bài 4 phân tích
3x^2-30x+75
xy -x^2-x^2-x
x^2-7x-8
4x^3 +8x^2y+4xy^2-16x
xy+xz -2y-2z
x^2+6x+9-y^3
a) A = \(3x^2-30x+75=3\left(x^2-10x+25\right)=3\left(x-5\right)^2\)
b) B = \(xy-x^2-x^2-x=xy-2x^2-x=x\left(y-2x-1\right)\)
c) C= \(x^2-7x-8=x^2-7x+12,25-20,25=\left(x-3,5\right)^2-20,25\)
1. Tìm max hoặc min:
a. A = x^2 - 5x - 1
b. B = 1/4x - x + 5.
c. C = x^2 - 4xy + 7y^2 - 2y +3
d. D = 5x^2 - xy + 1/24y^2 + 2x - 1
e. E = x^2 - 3xy + y - 2y - 1
2. Tìm x:
a. ( 2x - 3 )^2 - ( 4x + 1 ).( 4x - 1 ) = ( 2x - 1 ).( 3 - 7x )
b. 1/16x^2 - ( 3x + 5 ) = 0
c. 4.( x - 3 ) - ( x + 2 ) = 0