\(a.x+\left(x-1\right)+\left(x-2\right)+...+\left(x-100\right)=110x+8\)

\(\Leftrightarrow101x-\left(1+2+...+100\right)=110x+8\)

\(\Leftrightarrow101x-\frac{100\left(100+1\right)}{2}=110x+8\)

\(\Leftrightarrow101x-5050=110x+8\)

\(\Leftrightarrow101x-110x=8+5050\)

\(\Leftrightarrow-9x=5058\)

\(\Leftrightarrow x=5058\div\left(-9\right)\)

\(\Leftrightarrow x=-562\)

\(b.3x-7x+11x-15x+...+155x-159x=1680\)

\(\Leftrightarrow\left(3x-7x\right)+\left(11x-15x\right)+...+\left(155x-159x\right)=1680\)

\(\Leftrightarrow-4x-4x-...-4x=1680\)

\(\Leftrightarrow-80x=1680\)

\(\Leftrightarrow x=1680\div\left(-80\right)\)

\(\Leftrightarrow x=-21\)

`-11x-12=0`

`=> -11x=0+12`

`=>-11x=12`

`=>x=-12/11`

`---`

`7x-24=0`

`=>7x=0+24`

`=>7x=24`

`=>x=24/7`

`---`

`15x+30=0`

`=>15x=0-30`

`=>15x=-30`

`=>x= -2`

`---`

`-8x+16=0`

`=>-8x=0-16`

`=>-8x=-16`

`=>x=2`

`---`

`-7x-28=0`

`=>-7x=0+28`

`=>-7x=28`

`=>x= -4`

tìm nghiệm của đa thức phải ko ạ vì bạn cx gửi tưởng tự kiểu này

1)

`-11x-12=0`

`<=>-11x=12`

`<=>x=-12/11`

2)

`7x-24=0`

`<=>7x=24`

`<=>x=24/7`

3)

`15x+30=0`

`<=>15x=-30`

`<=>x=-2`

`-8x+16=0`

`<=>-8x=-16`

`<=>x=2`

5)

`-7x-28=0`

`<=>-7x=28`

`<=>x=-4`

a) Ta có: \(x^2-x-12=0\)

\(\Leftrightarrow\left(x-4\right)\left(x+3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-3\end{matrix}\right.\)

b) Ta có: \(x^2+3x-18=0\)

\(\Leftrightarrow\left(x+6\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-6\\x=3\end{matrix}\right.\)

a: \(=-2x^2\cdot3x+2x^2\cdot4X^3-2x^2\cdot7+2x^2\cdot x^2\)

\(=8x^5+2x^4-6x^3-14x^2\)

b: \(=2x^3-3x^2-5x+6x^2-9x-15\)

\(=2x^3+3x^2-14x-15\)

c: \(=\dfrac{-6x^5}{3x^3}+\dfrac{7x^4}{3x^3}-\dfrac{6x^3}{3x^3}=-2x^2+\dfrac{7}{3}x-2\)

d: \(=\dfrac{\left(3x-2\right)\left(3x+2\right)}{3x+2}=3x-2\)

e: \(=\dfrac{2x^4-8x^3-6x^2-5x^3+20x^2+15x+x^2-4x-3}{x^2-4x-3}\)

=2x^2-5x+1

\(A=3x^2y^3-5x^2+3x^3y^2\)

bậc 5, hệ số 3 

bạn xem lại đề B nhé 

A=15x²y²+7x²-8x³y²-12x²+11x³y²-12x²y²

A= (15x²y²-12x²y²)+(7x²-12x²)+(-8x³y²+11x³y²)

A= 3x²y²-5x²+3x³y²

Bậc là: 5

Hệ số cao nhất: 3

\(B=3x^5y+\left(\dfrac{-1}{3}\right)xy^4+34x^2y^3-\dfrac{1}{2}x^5y+2xy^4-x^2y^3\\ B=\dfrac{5}{2}x^5y+\dfrac{7}{3}xy^4-\dfrac{1}{4}x^2y^3\)

bậc là:6

hệ số cao nhất là:\(\dfrac{7}{3}\)

1) (7x-4y)(15a-9b)

2) (x+1)(7x+6)

3) (x-1)(5x-6)

4) (x+2)(x-5)

5) (x+7)(x-6)

6) (2x-3)(3x+1)

7) (3x+7)(5x-2)

Tk mình nha!!!>.<

a)

A=(x^3+3x^2+3x+1)+4(x^2+2x+1)+7(x+1)

A=(x+1)^3+4(x+1)^2+7(x+1)

A=(x+1)[(x+1)^2+4(x+1)+7)]

b)

B=x^3-3x^2+4

=(x^3+x^2)-4(x^2-1)

B=(x+1)[x^2-4(x-1)]

=(x+1)[x^2-4x+4)

=(x+1)(x-2)^2

c)

c=(x^3+3x^2+3x+1)-(x^2-1)

=(x+1)^3-(x-1)(x+1)[

=(x+1)[(x+1)^2-(x-1)]

C=(x+1)[(x^2+x+2)

d)

D=(x^3+x^2)+(5x^2+5x)+(6x+6)

D=(x+1)[x^2+5x+6]

D=(x+1)(x+2)(x+3)

a: \(\Leftrightarrow\left(x+12-3x\right)\left(x+12+3x\right)=0\)

=>(-2x+12)(4x+12)=0

=>x=-3 hoặc x=6

b: \(\Leftrightarrow20x^3-15x^2+45x-45=0\)

=>\(x\simeq0.93\)

d: =>-4x+28+11x=-x+3x+15

=>7x+28=2x+15

=>5x=-13

=>x=-13/5

e: \(\Leftrightarrow4x^3-12x+x=4x^3-3x+5\)

=>-9x=-3x+5

=>-6x=5

=>x=-5/6

x + 2 x - 3 = x -  x  + 3 x  - 3 =  x  ( x  - 1) + 3( x  - 1) = ( x  - 1)( x  + 3)

a) Với điểu kiện x ≥ 0; x ≠ 1 ta có: