Question

1. Phân tích...nhóm hạng tử

a) x² + 4x + 3

b) 2x² + 3x - 5

c) 16x - 5x² - 3

d) x² + 5x - 6

e) 7x - 6x² - 2

Answer 1

a)x²+4x+3

=x²+x+3x+3

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

=(x+1)(x+3)

b)2x²+3x-5

=2x²-2x+5x-5

=2x(x-1)+5(x-1)

=(x-1)(2x+5)

c)16x-5x²-3

=-5x²+16x-3

=-5x²+15x+x-3

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

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

d)x²+5x-6

=x²-x+6x-6

=x(x-1)+6(x-1)

=(x-1)(x+6)

e)7x-6x²-2

=-6x2+7x-2

=-6x²+4x+3x-2

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

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

Answer 2

a, theo đề ra ta có:

= x² + x + 3x + 3

= ( x² + x ) + ( 3x + 3 )

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

= ( x + 3 ). ( x + 1 )

Answer 3

b, theo đề ra ta có :

= 2x² - 2x + 5x - 5

= ( 2x² - 2x ) + ( 5x - 5 )

= 2x ( x - 1 ) + 5 ( x - 1 )

= ( 2x + 5 ). ( x - 1 )

Answer 4

d, theo đề ra ta có :

= x² - x + 6x - 6

= ( x² - x ) + ( 6x - 6 )

= x ( x - 1 ) + 6 ( x - 1 )

= ( x + 6 ). ( x - 1 )