23x+12x+27x=372
x+2x+3x+.....+15x=840
(2x-11)(5x -40)=0
làm 3 câu ạ
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!
Tính:
a) (x^5 +12x^2 + 5x) : (3x)
b) (-5x^4 + 15x^3 - 18x) : (-5x)
c) (-x^6 +5x^4 - 2x^3) : 0,5x
a: \(=\dfrac{x^5}{3x}+\dfrac{12x^2}{3x}+\dfrac{5x}{3x}=\dfrac{1}{3}x^4+4x+\dfrac{5}{3}\)
b: \(=\dfrac{-5x^4}{-5x}-\dfrac{15x^3}{5x}+\dfrac{18x}{5x}=x^3-3x^2+\dfrac{18}{5}\)
c: \(=\dfrac{-x^6}{0.5x}+\dfrac{5x^4}{0.5x}-\dfrac{2x^3}{0.5x}=-2x^5+10x^3-4x^2\)
Tìm x:
a) 4x(3x-7)-6(2x^2-5x+1)=12
b) (5x+3)(4x-1)+(10x-7)(-2x+3)=27
c) (8x-5)(3x+2)-(12x+7)(2x-1)=17
d) (5x+9)(6x-1)-(2x-3)(15x+1)=-190
a) 4x(3x-7)-6(2x2-5x+1)=12
=>4x.3x-4x.7-6.2x2-6.(-5x)-6.1=12
=>12x2-28x-12x2+30x-6=12
=>2x-6 =12
=>2x =12+6
=>2x =18
=>x =18:2
=>x =6
b)(5x+3)(4x-1)+(10x-7)(-2x+3)=27
=>5x.4x-5x.1+3.4x+3.(-1)+10x.(-2x)+10x.3-7.-(2x)-7.3=27
=>20x2-5x+12x-3-20x2+30x+14x-21=27
=>39x-36 =27
=>39x =27+36
=>39x =63
=>x =63:39
=>x =21/13
c) (8x-5)(3x+2)-(12x+7)(2x-1)=17
=>8x.3x+8x.2-5.3x-5.2-12x.2x-12x.(-1)+7.2x+7.(-1)=17
=>24x2+16x-15x-10-24x2+12x+14x-7=17
=>27x-17 =17
=>27x =17+17
=>27x =34
=>x =34:27
=>x =34/27
d) (5x+9)(6x-1)-(2x-3)(15x+1)=-190
=>30x2-5x+63x-9 - 30x2-2x-45x-3=-190
=>11x-12 =-190
=>11x =-190+12
=>11x =-178
=>x = -178:11
=>x =-178/11
Phân tích các đa thức sau thành nhân tử?
a)x^4+5x^3-23x^2-117x-90
d)x^3-9x^2+26x-24
f)(x^2-3x+2)(x^2-3x-6)+12
g)4(x^2+15x+50)(x^2+18x+72)-3x^2
h)27x^3-27x^2+18x-4
a: x^3-7x-6
=x^3-x-6x-6
=x(x-1)(x+1)-6(x+1)
=(x+1)(x^2-x-6)
=(x-3)(x+2)(x+1)
b: =2x^3+x^2-2x^2-x+6x+3
=x^2(2x+1)-x(2x+1)+3(2x+1)
=(2x+1)(x^2-x+3)
c: =2x^3-3x^2-2x^2+3x+2x-3
=x^2(2x-3)-x(2x-3)+(2x-3)
=(2x-3)(x^2-x+1)
d: =2x^3+x^2+2x^2+x+2x+1
=(2x+1)(x^2+x+1)
e: =3x^3+x^2-3x^2-x+6x+2
=(3x+1)(x^2-x+2)
f: =27x^3-9x^2-18x^2+6x+12x-4
=(3x-1)(9x^2-6x+4)
a) \(x^3-7x-6\)
\(=x^3-x-6x-6\)
\(=\left(x^3-x\right)-\left(6x+6\right)\)
\(=x\left(x^2-1\right)-6\left(x+1\right)\)
\(=x\left(x+1\right)\left(x-1\right)-6\left(x+1\right)\)
\(=\left(x+1\right)\left(x^2-x-6\right)\)
b) \(2x^3-x^2+5x+3\)
\(=2x^3+x^2-2x^2-x+6x+3\)
\(=\left(2x^3+x^2\right)-\left(2x^2+x\right)+\left(6x+3\right)\)
\(=x^2\left(2x+1\right)-x\left(2x+1\right)+3\left(2x+1\right)\)
\(=\left(x^2-x+3\right)\left(2x+1\right)\)
c) \(2x^3-5x^2+5x+1\)
\(=2x^3-3x^2-2x^2+3x+2x-3\)
\(=\left(2x^3-3x^2\right)-\left(2x^2-3x\right)+\left(2x-3\right)\)
\(=x^2\left(2x-3\right)-x\left(2x-3\right)+\left(2x-3\right)\)
\(=\left(x^2-x+1\right)\left(2x-3\right)\)
d) \(2x^3+3x^2+3x+1\)
\(=2x^3+x^2+2x^2+x+2x+1\)
\(=\left(2x^3+x^2\right)+\left(2x^2+x\right)+\left(2x+1\right)\)
\(=x^2\left(2x+1\right)+x\left(2x+1\right)+\left(2x+1\right)\)
\(=\left(2x+1\right)\left(x^2+x+1\right)\)
e) \(3x^3-2x^2+5x+2\)
\(=3x^3+x^2-3x^2-x+6x+2\)
\(=\left(3x^3+x^2\right)-\left(3x^2+x\right)+\left(6x+2\right)\)
\(=x^2\left(3x+1\right)-x\left(3x+1\right)+2\left(3x+1\right)\)
\(=\left(3x-1\right)\left(x^2-x+2\right)\)
f) \(27x^3-27x^2+18x-4\)
\(=27x^3-9x^2-18x^2+6x+12x-4\)
\(=\left(27x^3-9x^2\right)-\left(18x^2-6x\right)+\left(12x-4\right)\)
\(=9x^2\left(3x-1\right)-6x\left(3x-1\right)+4\left(3x-1\right)\)
\(=\left(3x-1\right)\left(9x^2-6x+4\right)\)
18x - 19 = 21+8x
g)18- 4x = -20-6x
h)-15x - 24 = - 7x +32
i) 15x- 3(4x - 6) = - 12+ 36
k) -10 x - 27 = - 7x +33
m) -17 x - 24 = - 9x - 40
n) -23x + 25 = - 18x +75
p) - 5x+ 7( 2x-3) = 4( x - 4)
q)24- 6(3x + 1) = -5( 4x- 4 ) - 8
r) 18-4. (6-2x) = -3.(4x +5 ) - 11
s) - 5. ( 4x-5) - 14 = 6.(2 - 3x) - 10x-9
giúp mik với giải cả cách làm nhé
18x -19 = 21 + 8x
18 x - 8x = 21 + 19
10 x = 40
x =4
g) 18 -4x=-20-6x
-4x + 6x = -20 - 18
2x = -38
x= -19
k, -10 \(x\) - 27 = -7\(x\) + 33
-27 - 33 = -7\(x\) + 10\(x\)
3\(x\) = -60
\(x\) - 20
m, -17\(x\) - 24 = -9\(x\) - 40
-24 + 40 = -9\(x\) + 17\(x\)
8\(x\) = 16
\(x\) = 2
h)-15x -24 = 7x + 32
-15x - 7x = 32 + 24
-22x = 56
x = \(-\dfrac{14}{5}\)
i)15x -3(4x -6)=-12+36
15x - 12x + 18 = 24
3x + 18 = 24
3x = 24 - 18
3x = 6
x=2
Bài: giải các phương trình sau:
a/2x(27x^2-8)+4(2x-6)(2x+6)-(3x-4)(5x+2)=2(3x-4)(9x^2+12x+16).
b/ 4-x/2018-2=3-x/2019-x/1011
LÀM TÍNH CHIA:
a) \(\left(6x^6+2x^5-2x^4-15x^3+x^2+7x+2\right):\left(3x^2+x-1\right)\)
b) \(\left(-6x^4+5x^3+17x^2-23x+7\right):\left(-3x^2-2x+7\right)\)