(x3-3x2+2x-6):(x-3)
(x3-8):(x-2)
(x3-3x2+2x-6):(x-3)
(x3-8):(x-2)
Lời giải:
$(x^3-3x^2+2x-6):(x-3)=[x(x-3)+2(x-3)]:(x-3)$
$=(x-3)(x+2):(x-3)=x+2$
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$(x^3-8):(x-2)=(x-2)(x^2+2x+4):(x-2)=x^2+2x+4$
Tìm x, biết:
a) 2(5x-8)-3(4x-5) = 4(3x-4) + 11;
b) 2 x ( 6 x - 2 x 2 ) + 3 x 2 ( x - 4 ) = 8;
c) 2 ( x 3 - 1 ) - 2 x 2 ( x + 2 x 4 ) + ( 4 x 5 + 4 ) x = 6;
d)(2x)2(4x-2)-(x3 -8x2) = 15.
a) x = 2 7 b) x = 2.
c) x = 2 d) x = 1.
Thực hiện phép tính:
1)(x3-8):(x-2)
2)(x3-1):(x2+x+1)
3)(x3+3x2+3x+1):(x2+2x+1)
4)(25x2-4y2):(5x-2y)
1) \(\left(x^3-8\right):\left(x-2\right)=\left[\left(x-2\right)\left(x^2+2x+4\right)\right]:\left(x-2\right)=x^2+2x+4\)
2) \(\left(x^3-1\right):\left(x^2+x+1\right)=\left[\left(x-1\right)\left(x^2+x+1\right)\right]:\left(x^2+x+1\right)=x-1\)
3) \(\left(x^3+3x^2+3x+1\right):\left(x^2+2x+1\right)=\left(x+1\right)^3:\left(x+1\right)^2=x+1\)
4) \(\left(25x^2-4y^2\right):\left(5x-2y\right)=\left[\left(5x-2y\right)\left(5x+2y\right)\right]:\left(5x-2y\right)=5x+2y\)
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: \(=\left(x-y-z\right)^2\)
a)A=3x(2/3x2-3x4)+(3x2)(x3-1)+(-2+9).x2-12
b)B=x(2x3+x+2)-2x2(x2+1)+x2-2x+1
c)C=x.(2x+1)-x2(x+2)+x3-x+3
a, \(A=2x^3-9x^5+3x^5-3x^2+7x^2-12=-6x^5+2x^3+4x^2-12\)
b, \(B=2x^4+x^2+2x-2x^3-2x^2+x^2-2x+1=2x^4-2x^3+1\)
c, \(C=2x^2+x-x^3-2x^2+x^3-x+3=3\)
Giải pt : a) 2/-x2+6x-8 - x-1/x-2 = x+3/x-4
b) 2/x3-x2-x+1 = 3/1-x2 - 1/x+1
c) x+2/x-2 - 2/x2-2x = 1/x
d) 5/-x2+5x-6 + x+3/2-x = 0
e) x/2x+2 - 2x/x2-2x-3 = x/6-2x
f) 1/x-1 - 3x2/x3-1 = 2x/x2+x-1
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) |
1.rút gọn bt A= (x+2)3-2x(x+3)+(x3-8):(x-2)
2. tìm x biết:
a. 3x2-12x=0
b.4x2-1-4(1-2x)=0
Bài 13. Cho 2 đa thức: P(x)= 4x2 + x3 - 2x +3 -x-x3 +3x -2x2
Q(x)= 3x2 - 3x +2 -x3 +2x - x2
b)Tìm đa thức R(x) sao cho P(x) - Q(x) - R(x) =0
`P(x)=\(4x^2+x^3-2x+3-x-x^3+3x-2x^2\)
`= (x^3-x^3)+(4x^2-2x^2)+(-2x-x+3x)+3`
`= 2x^2+3`
`Q(x)=`\(3x^2-3x+2-x^3+2x-x^2\)
`= -x^3+(3x^2-x^2)+(-3x+2x)+2`
`= -x^3+2x^2-x+2`
`P(x)-Q(x)-R(x)=0`
`-> P(X)-Q(x)=R(x)`
`-> R(x)=P(x)-Q(x)`
`-> R(x)=(2x^2+3)-(-x^3+2x^2-x+2)`
`-> R(x)=2x^2+3+x^3-2x^2+x-2`
`= x^3+(2x^2-2x^2)+x+(3-2)`
`= x^3+x+1`
`@`\(\text{dn inactive.}\)
a: P(x)-Q(x)-R(x)=0
=>R(x)=P(x)-Q(x)
=2x^2+3+x^3-2x^2+x-2
=x^3+x+1