C3 .7x3-3x2-3x-1
C4 .2x3-5x2+x-2
C1 .3x3-5x-2
C2 ,(2x-3)3+(6x-17)3
C3 .7x3-3x2-3x-1
C4 .2x3-5x2+x-2
giúp với
C2: (2x - 3)3 + (6x - 17)3
= (2x - 3 + 6x - 17)\(\left[\left(2x-3\right)^2-\left(2x-3\right)\left(6x-17\right)+\left(6x-17\right)^2\right]\)
= (8x - 20)(4x2 - 12x + 9 - 12x2 + 34x + 18x - 51 + 36x2 - 204x + 289)
= (8x - 20)(4x2 - 12x2 + 36x2 - 12x + 34x + 18x - 204x + 9 - 51 + 289)
= (8x - 20)(28x2 - 164x + 247)
Câu 1:
Ta có: \(3x^3-5x-2\)
\(=3x^3+3x^2-3x^2-3x-2x-2\)
\(=\left(x+1\right)\left(3x^2-3x-2\right)\)
Bài 5:
1) a) Cho hai đa thức:
P (x) = 5x2 + 3x3 - 5x2 + 2x3 – 2 +4x – 4x2 + x3
Q(x) = 6x – x3 + 5 – 4x3 + 6 – 3x2 – 7x2
Tính M(x) = P(x) + Q(x)
b) Tìm C(x) biết: (5x2 + 9x – 3x4 + 7x3 -12) + C(x) = -2x3 + 9 – 6x + 7x4 -2x3
2) Tìm nghiệm của các đa thức sau
a) 4x - b) x2 – 4x +3
a: P(x)=6x^3-4x^2+4x-2
Q(x)=-5x^3-10x^2+6x+11
M(x)=x^3-14x^2+10x+9
b: \(C\left(x\right)=7x^4-4x^3-6x+9+3x^4-7x^3-5x^2-9x+12\)
=10x^4-11x^3-5x^2-15x+21
1. (x3 – 3x2 + x – 3) : (x – 3) 2. (2x4 – 5x2 + x3 – 3 – 3x) : (x2 – 3) 3. (x – y – z)5 : (x – y – z)3 4. (x2 + 2x + x2 – 4) : (x + 2) 5. (2x3 + 5x2 – 2x + 3) : (2x2 – x + 1) 6. (2x3 – 5x2 + 6x – 15) : (2x – 5)
1: \(=x^2+1\)
3: \(=\left(x-y-z\right)^2\)
Cứu với ạ
Làm tính chia
1) (x3 – 3x2 + x – 3) : (x – 3) 2) (2x4 – 5x2 + x3 – 3 – 3x) : (x2 – 3)
3) (x – y – z)5 : (x – y – z)3 4) (x2 + 2x + x2 – 4) : (x + 2)
5) (2x3 + 5x2 – 2x + 3) : (2x2 – x + 1) | 6) (2x3 – 5x2 + 6x – 15):(2x – 5) |
Tìm bậc của mỗi đa thức sau
a) f (x) = 3x2 + 2x3 - 6x - 2
b) g(x) = 5x2 + 9 - 2x3 - 3x2 - 4x + 2x3 - 2
f (x) = 3x2 + 2x3 - 6x - 2
bậc của đa thức là: 3
g(x) = 5x2 + 9 - 2x3 - 3x2 - 4x + 2x3 - 2
g(x) = ( 5x2 - 3x2 ) + ( 9 -2) + ( - 2x3 + 2x3 ) - 4x
g(x) = 2x2 + 7 - 4x
bậc của đa thức là : 2
a)(-3x2+5x2-9x+15):(-3x+5)
b)(x4-2x3+2x-1):(x2-1)
c)(5x4+9x3-2x2-4x-8):(x-1)
d)(5x3+14x2+12x+8):(x+2)
b: \(\dfrac{\left(x^2-1\right)\left(x^2+1\right)-2x\left(x^2-1\right)}{x^2-1}\)
\(=x^2-2x+1\)
\(=\left(x-1\right)^2\)
c: \(=\dfrac{5x^4-5x^3+14x^3-14x^2+12x^2-12x+8x-8}{x-1}\)
\(=5x^3+14x^2+12x+8\)
Tính:
1. ( x - 2 ) ( 3x + 1 )
2. ( 8x4y3 - 12x3y3 + 6x3y4 )
3. ( 3x3y2 + 6x2y3 - 12xy4 ) : 3xy
4. ( 3x3y2 + 6x2y3 - 12xy4 ) : 4xy
5. ( 2x3 - 5x2 + 7x - 6 ) : ( 2x - 3 )
6. ( x4 - x3 + 3x2 + x + 2 ) : ( x2 - 1 )
\(1,=3x^2-6x+x-2=3x^2-5x-2\\ 2,??\\ 3,=3x^3y^2:3xy+6x^2y^3:3xy-12xy^4:3xy=x^2y+2xy^2-4y^3\\ 4,=3x^3y^2:4xy+6x^2y^3:4xy-12xy^4:4xy\\ =\dfrac{3}{4}x^2y+\dfrac{3}{2}xy^2-3x^3\\ 5,\left(2x^3-5x^2+7x-6\right):\left(2x-3\right)=x^2-x+2\\ 6,\left(x^4-x^3+3x^2+x+2\right):\left(x^2-1\right)=x^2-x+4\left(dư6\right)\)
1: =3x^2+x-6x-2=3x^2-5x-2
3: =x^2y+2xy^2-4y^3
4: =3/4x^2y+3/2xy^2-3y^3
5: \(=\dfrac{2x^3-3x^2-2x^2+3x+4x-6}{2x-3}=x^2-x+2\)
1) (1-x)(5x+3)=(3x-7)(x-1)
2) (x-2)(x+1)=x2-4
3) 2x3+3x2-32x=48
4) x2+2x-15=0
5) 2x(2x-3)=(3-2x)(2-5x)
6) x3-5x2+6x=0
7) (x2-5)(x+3)=0
8) (x+7)(3x-1)=49-x2
\(\left(1-x\right)\left(5x+3\right)=\left(3x-7\right)\left(x-1\right)\)
\(< =>\left(1-x\right)\left(5x+3+3x-7\right)=0\)
\(< =>\left(1-x\right)\left(8x-4\right)=0\)
\(< =>\orbr{\begin{cases}1-x=0\\8x-4=0\end{cases}< =>\orbr{\begin{cases}x=1\\x=\frac{1}{2}\end{cases}}}\)
\(\left(x-2\right)\left(x+1\right)=x^2-4\)
\(< =>\left(x-2\right)\left(x+1\right)=\left(x-2\right)\left(x+2\right)\)
\(< =>\left(x-2\right)\left(x+1-x-2\right)=0\)
\(< =>-1\left(x-2\right)=0\)
\(< =>2-x=0< =>x=2\)
\(2x^3+3x^2-32x=48\)
\(< =>x^2\left(2x+3\right)-16\left(2x+3\right)=0\)
\(< =>\left(x^2-16\right)\left(2x+3\right)=0\)
\(< =>\left(x-4\right)\left(x+4\right)\left(2x+3\right)=0\)
\(< =>\hept{\begin{cases}x=4\\x=-4\\x=-\frac{3}{2}\end{cases}}\)
Cho hai đơn thức A ( x ) = - 2 x 3 + 9 - 6 x + 7 x 4 - 2 x 2 , B ( x ) = 5 x 2 + 9 x - 3 x 4 + 7 x 3 - 12 . Tính tổng A(x) + B(x) của hai đa thức
A. 4 x 4 - 5 x 3 + 3 x 2 + 3 x + 3
B. 4 x 4 + 5 x 3 + 3 x 2 + 3 x - 3
C. - 2 x 4 + 5 x 3 - 3 x 2 + 3 x - 3
D. 7 x 4 + 5 x 3 + 3 x 2 - 3 x - 3
Ta có:
A(x) + B(x) = -2x3 + 9 - 6x + 7x4 - 2x2+ 5x2 + 9x - 3x4 + 7x3 - 12
= 4x4 + 5x3 + 3x2 + 3x - 3. Chọn B