Question

12x²+4x-1 x²-（a+b）xy+aby² xy-1+x-y x²-（2

Answer 1

1. 12x2+4x-1=12(x+1/2)(x-1/6)

2. x2-(a+b)xy+aby2=(x-ay)(x-by)

3. xy-1+x-y=(x-1)(1+y)

4. x2-(2a-1)x+a2-a=(x-a)(x-a+1)

6. 5x2+4x-1=(x+1)(5x-1)

7. x2-2x-1= (x-1)2-2=(x-1+√2) (x-1-√2)

8. y2+2xy-15x2=(y+5x)(y-3x)

10. x2-5x+3= (x-5/2)2-13/4=(x-5/2+√13/2)( x-5/2-√13/2)

11. 3x2+4xy-y2=3(x+2y/3)2-7y2/3=[√3(x+2y/3)+√21/3y] [√3(x+2y/3)-√21/3y]