(x+3)^3-8x^3
(4x^2-3x-18)^2 (-4x^2+3x^2)^2
(x-1/2x-3 - 3x/4x+6 + 7x-2x^2-1/18-8x^2)/(1/6-4x)
tìm x biết:
a)(2x+2)(2x-2)-4x(x+5)=8
b)(4x+5)(4x-5)-8x(2x-7)=11
c)(1/2x-3)(1/2x+3)-1/4x(x+5)=11/2
d)(3x+2)(3x-2)-4x(x+2-5x2=18
\(a.x=-0,6\)
\(c.x=-11,6\)
Pt nhju ak!!!
tìm x biết
a) (6x-3) (2x+4) + (4x-1) (5-3x) = -21
b) 6x (3x+5) - 2x (9x-2) + (17-x) (x-1) + x (x-18) =0
c) (15-2x) (4x+1) - (13-4x) (2x-3) - (x-1) (x+2) + x2=52
d) (8x-3) (3x+2) - (4x+7) (x+4) = (2x+1) (5x-1) - 33
Rút gọn hết ta được :
a/ 41x - 17 = -21
=> 41x = -4 => x = 4/41
b/ 34x - 17 = 0
=> 34x = 17
=> x = 17/34 = 1/2
c/ 19x + 56 = 52
=> 19x = -4
=> x = -4/19
d/ 20x2 - 16x - 34 = 10x2 + 3x - 34
=> 10x2 - 19x = 0
=> x(10x - 19) = 0
=> x = 0
hoặc 10x - 19 = 0 => 10x = 19 => x = 19/10
Vậy x = 0 ; x = 19/10
Rút gọn hết ta được :
a/ 41x - 17 = -21
=> 41x = -4 => x = 4/41
b/ 34x - 17 = 0
=> 34x = 17
=> x = 17/34 = 1/2
c/ 19x + 56 = 52
=> 19x = -4
=> x = -4/19
d/ 20x 2 - 16x - 34 = 10x 2 + 3x - 34
=> 10x 2 - 19x = 0
=> x(10x - 19) = 0
=> x = 0 hoặc 10x - 19 = 0
=> 10x = 19
=> x = 19/10
Vậy x = 0 ; x = 19/10
a) ( 6x - 3 ) ( 2x + 4 ) + ( 4x - 1 ) ( 5 - 3x ) = -21
<=> 12x2 + 24x - 6x - 12 + 20x - 12x2 - 5 + 3x = -21
<=> 41x = -21 + 12 + 5
<=> 41x = -4
<=> x = -4/41
Phân tích các đa thức sau thành nhân tử:
a) -16a^4b^6 - 24a^5b^5 - 9a^9b^4
b) ( 3x - 1)^2 - 16
c) ( 3x + 1)^2 - 4( x - 2 )^2
d) ( ax + by) ^2 - ( ay + bx )^2
e) ( 4x^2 - 3x - 18)^2 - ( 4x^2 + 3x )^2
g) 8x^3 - 64
h) 8x^3 - 27
i) x^3 + 6x^2 + 12x + 8
k) x^3 + 3/2x^2 + 3/4x + 1/8
Giúp mình nhé, mình cần gấp lắm
: Tìm x, biết:
a) 3x( 4x- 1) - 2x(6x- 3 )=30 b) 2x(3-2x) + 2x(2x-1)=15
c) (5x-2)(4x-1) + (10x +3)(2x - 1)=1 d) (x+2) (x+2)- (x -3)(x+1) = 9
e) (4x+1)(6x-3) = 7 + (3x – 2)(8x + 9) g) (10x+2)(4x- 1)- (8x -3)(5x+2) =14
`@` `\text {Ans}`
`\downarrow`
`a)`
`3x(4x-1) - 2x(6x-3) = 30`
`=> 12x^2 - 3x - 12x^2 + 6x = 30`
`=> 3x = 30`
`=> x = 30 \div 3`
`=> x=10`
Vậy, `x=10`
`b)`
`2x(3-2x) + 2x(2x-1) = 15`
`=> 6x- 4x^2 + 4x^2 - 2x = 15`
`=> 4x = 15`
`=> x = 15/4`
Vậy, `x=15/4`
`c)`
`(5x-2)(4x-1) + (10x+3)(2x-1) = 1`
`=> 5x(4x-1) - 2(4x-1) + 10x(2x-1) + 3(2x-1)=1`
`=> 20x^2-5x - 8x + 2 + 20x^2 - 10x +6x - 3 =1`
`=> 40x^2 -17x - 1 = 1`
`d)`
`(x+2)(x+2)-(x-3)(x+1)=9`
`=> x^2 + 2x + 2x + 4 - x^2 - x + 3x + 3=9`
`=> 6x + 7 =9`
`=> 6x = 2`
`=> x=2/6 =1/3`
Vậy, `x=1/3`
`e)`
`(4x+1)(6x-3) = 7 + (3x-2)(8x+9)`
`=> 24x^2 - 12x + 6x - 3 = 7 + (3x-2)(8x+9)`
`=> 24x^2 - 12x + 6x - 3 = 7 + 24x^2 +11x - 18`
`=> 24x^2 - 6x - 3 = 24x^2 + 18x -11`
`=> 24x^2 - 6x - 3 - 24x^2 + 18x + 11 = 0`
`=> 12x +8 = 0`
`=> 12x = -8`
`=> x= -8/12 = -2/3`
Vậy, `x=-2/3`
`g)`
`(10x+2)(4x- 1)- (8x -3)(5x+2) =14`
`=> 40x^2 - 10x + 8x - 2 - 40x^2 - 16x + 15x + 6 = 14`
`=> -3x + 4 =14`
`=> -3x = 10`
`=> x= - 10/3`
Vậy, `x=-10/3`
Phân tích đa thức thành nhân tử:
a) x^3 + 3x^2- 3x-1
b)x^3 - 3x^2-3x-1
c) (a^2 +b^2+ ab)^2- a^2b^2-c^2a^2-b^2c^2
d)x^3 - 4x^2-4x+1
e) x^4 - 4x^3- 8x^2+8x
Giúp mình với nhé!!!
a ) \(x^3+3x^2-3x+1\)
\(=x^3-3x+3x^2-1\)
\(=\left(x-1\right)^3\)
c/ (x + 1)(x + \(\frac{\sqrt{21}-5}{2}\))(x + \(\frac{-\sqrt{21}-5}{2}\))
Phân tích các đa thức sau thành nhân tử
a)x^2.(y-z)+y^2.(z-x)+z^2.(x-y)
b) (2x+5)^2-(x-9)^2
c)(2x+3)^2- 25.(x-1)^2
d)(4x^2-3x-18)^2-(4x^2+3x)^2
e)-4x^2+12xy-9y^2+25
f) 8x^2-2
g)8x^3-64
h)125x^3+1
Tìm x biết:
a) 40 - 3 . (4 - 3x) = 8x - 2
b) -34 + 3 . (-x + 7) = 4x - 18
c) 4 . (3x - 2) = -3 . (x - 1) + 4
a)2(x-4)^2-4x(4-x)=0
b)4x^2-8x=0
c)3x^2+6x=0
d)8x^2+4x^3=0
\(a,< =>2\left(x-4\right)^2+4x\left(x-4\right)=0< =>\left(x-4\right)\left(2x-8+4x\right)=0\)\(< =>\left(x-4\right)\left(6x-8\right)=0< =>\left[{}\begin{matrix}x=4\\x=\dfrac{4}{3}\end{matrix}\right.\)
b,\(< =>4x\left(x-2\right)=0< =>\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\)
c,\(< =>3x\left(x+2\right)=0< =>\left[{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\)
d,\(< =>4x^2\left(2+x\right)=0< =>\left[{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\)