中三數 - 因式分解`

寫明,,我係中二來,,唔識既話請原諒丫

1) 2x^2 7x-4
=(2x-1)(x 4)
解釋: 2x -1
X
x 4
8x -x = 7x

2)4x^2 7x-2
=(4x-1)(x 2)
解釋: 4x -1
X
x 2
8x-x=7x

3) 2 6x^2 7x
= 6x^2 7x 2
=(2x 1)(3x 2)
解釋: 2x 1
X
3x 2
4x+ 3x=7x

4) 5 2x-3x^2
=-(3x^2-2x-5)
=-(x+1)(3x-5)
解釋: x 1
X
3x -5
-5x +3x = -2x

5) 3xy^3 z-6x^2y^2z^3
=3xzy^2( y -2xz^2) 一次過抽3xy^2,,,唔會扣步驟分

1. 2x²+7x-4
=(x+4)(2x-1)

2.4x²+7x-2
=(4x-1)(x+2)

3. 2+6x²+7x
=6x²+7x+2
=(2x+1)(3x+2)

4. 5+2x-3x²
=-3x²+2x+5
=-(3x²-2x-5)....x²係數要正數
=(3x-5)(x+1)

5. 3xy^3 z -6x²y²z^3
=3xy²z(y-2xz²)

1)

2x^2 + 7x - 4

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

2)

4x^2 + 7x - 2

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

3)

2 + 6x^2 + 7x

= 6x^2 + 7x + 2

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

4)

5 + 2x - 3x^2

= - 3x^2 + 2x + 5

= - (3x^2 - 2x - 5)

= - (3x + 5)(x - 1)

= (3x + 5)(1 - x)

5)

3x(y^3)z - 6(x^2)(y^2)(z^3)

= 3[x(y^3)z - 2(x^2)(y^2)(z^3)]

= 3x[(y^3)z - 2x(y^2)(z^3)]

= 3xz[y^3 - 2x(y^2)(z^2)]

= 3x(y^2)z * (y - 2xz^2)