(6x³-2x+10x+2) : (2x²+3)
: 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`
làm phép chia
1) (x^6 - 2x^4 + 6x^3 - 4x^2) : 6x^2
2) (-2x^5 = 3x^2 - 4x^3) : 2x^2
3) (15x^3 - 10x^2 + x - 2) : (x - 2)
4) (2x^4 -3x^3 - 3x^2 + 6x - 2) : (x^2 - 2)
làm phép chia :
a) (x^4 -2x^3 + 2x -1) : (x^2 - 1)
b) (x^3 -8) : (x^2 + 2x +4)
c) (x^6 - 2x^5 + 2x^4 + 6x^3 - 4x^2)n: 6x^2
d) (-2x^5 + 3x^2 - 4x^3) :2x^2
e) (15x^3 - 10x^2 + x - 2) : (x - 2)
f) (2x^4 - 3x^3 - 3x^2 + 6x - 2) : (x^2 - 2)
b: =x-2
d: \(=-x^3+\dfrac{3}{2}-2x\)
tìm x
1) (3x-2)(9x^2+6x+4)-(2x-5)(2x+5)=(3x-1)^3-(2x+3)^2+9x(3x-1)
2) (2x+1)^3-(3x+2)^2=(2x-5)(4x^2+10x+25)+6x(2x+1)-9x^2
(2x^4y^3 +6x^3y^2 -10x^2y): (- 2x^2y)
2) 3x^2 + 3x - 6 ; 4) 6x^2 - 13x + 6 ;
5) 6x^2 + 13x + 6 ; 6) 6x^2 + 15x + 6 ;
7) 6x^2 - 15x + 6 ; 8) 6x^2 + 20x + 6 ;
9) 6x^2 - 20x + 6 ; 10) 6x^2 + 12x + 6 ;
11) 8x^2 - 2x - 3 ; 12) 8x^2 + 2x - 3 ;
13) -8x^2 + 5x + 3 ; 14) 8x^2 - 10x - 3 ;
15) 8x^2 + 10x - 3 ; 16) -8x^2 + 23x + 3 ;
17) 8x^2 - 23x - 3 ; 18) 10x^2 - 11x - 6 ;
19) -10x^2 + 11x + 6 ; 20) 10x^2 - 4x - 6 ;
HELP ME!!!
Mik quên mất ghi đề bài r ! Xin lỗi nhé ! Đề bài là:
Bài 2: Phân tích thành nhân tử ( bằng kĩ thuật tách hạng tử).
Đây là toàn bộ nội dung câu hỏi các bạn nhé!
C1.10x2=6x+8
C2.23x+10=23+13x
C3.9x-6=4x+1
C4.15x-12=11x+15
C5.21x+9=19-11x
C6.15+16x=8-3x
C7.19-4x=8x+23
C8.51-10x=3x-21
C9.8-6x=11-4x
C10.2(3x+4)-3(1-2x)=8x+10
C11.5(3-4x)-4(2x-5)=9-10x
C12.3(5x-6)-2(2x-5)=11x-10
C13.10x+5(3x-2)=25-10x
C14.6(2x-3)+3(3-5x)=8x-9
C15.3(4x-2)+2(6-2x)=10-6x
C16.5(3-6x)-4(2-2x)=4x-9
B2:tìm cặp số nguyên x, y thỏa mãn
X y+2x+y=0
nhiều quá bạn ơi , mk nghĩ bạn nên tách ra rồi hãy đăng lên
Bài 1:
16:
=>15-30x-8+8x=4x-9
=>-22x+7=4x-9
=>-26x=-16
=>x=8/13
15: \(\Leftrightarrow12x-6+12-4x=10-6x\)
=>8x+6=10-6x
=>14x=4
=>x=2/7
14: \(\Leftrightarrow12x-18+9-15x=8x-9\)
=>-3x-9=8x-9
=>x=0
13: \(\Leftrightarrow10x+15x-10=25-10x\)
=>25x-10=25-10x
=>35x=35
=>x=1
12: \(\Leftrightarrow15x-18-4x+10=11x-10\)
=>11x-8=11x-10(loại)
2) (2x+1)^3-(3x+2)^2=(2x-5)(4x^2+10x+25)+6x(2x+1)-9x^2
Tìm x
( 2x + 1 )3 - ( 3x + 2 )2 = ( 2x - 5 )( 4x2 + 10x + 25 ) + 6x( 2x + 1 ) - 9x2
⇔ 8x3 + 12x2 + 6x + 1 - ( 9x2 + 12x + 4 ) = 8x3 - 125 + 12x2 + 6x - 9x2
⇔ 8x3 + 12x2 + 6x + 1 - 9x2 - 12x - 4 = 8x3 + 3x2 + 6x - 125
⇔ 8x3 + 3x2 - 6x - 3 = 8x3 + 3x2 + 6x - 125
⇔ 8x3 + 3x2 - 6x - 3 - 8x3 - 3x2 - 6x + 125 = 0
⇔ -12x + 122 = 0
⇔ -12x = -122
⇔ x = 61/6
Bài 3 :Làm tính chia (2x^4 y^3 +6x^3y^2 -10x^2y) : (-2x^2y)
\(\frac{2x^4y^3+6x^3y^2-10x^2y}{-2x^2y}\)\(=\frac{2x^2y\left(x^2y^2+3xy-5\right)}{-2x^2y}\)\(=5-3xy-x^2y^2\)
1) 4x-10=0 2) 2x^3 + 6x^2 = x^2 + 3x 3) x - 5 = 3 - x 4) (-10x + 5 ) ( 2x - 8 ) = 0
1, \(4x-10=0\\ \Leftrightarrow x=\dfrac{5}{2}\)
vậy tập no S=\(\left\{\dfrac{5}{2}\right\}\)
2, \(2x^3+6x^2=x^2+3x\\ \Leftrightarrow2x^2\left(x+3\right)-x\left(x+3\right)=0\\ \Leftrightarrow x\left(2x-1\right)\left(x+3\right)=0\)
\(\Leftrightarrow\) \(x=0\) hoặc \(2x-1=0\) hoặc \(x+3=0\)
\(\Leftrightarrow\) \(x=0\) hoặc \(x=\dfrac{1}{2}\) hoặc \(x=-3\)
vậy tập no S=\(\left\{0,\dfrac{1}{2},-3\right\}\)
3, \(x-5=3-x\\ \Leftrightarrow2x=8\\ \Leftrightarrow x=4\)
vậy tập no S=\(\left\{4\right\}\)
4,\(\left(-10x+5\right)\left(2x-8\right)=0\)
\(\Leftrightarrow\) \(-10x+5=0\) hoặc \(2x-8=0\)
\(\Leftrightarrow\) \(x=\dfrac{1}{2}\) hoặc \(x=4\)
vậy tập no S=\(\left\{\dfrac{1}{2},4\right\}\)