Question

bài 1; phân tích đa thức sau thành hân tử

b, x mũ 2 + 4x + 3

b, x mũ 2 - 8x + 15

b, x mũ 2 + 2x - 8

b,x mũ 2 - x - 12

b, 4x mũ 2 + 4x - 3

 

Answer 1

bấm máy tính là ra đó :VV

Answer 2

b, x mũ 2 + 4x + 3 = ( x+ 1 ) ( x + 3 )

Answer 3

a) = x² + 3x + x + 3 = x( x + 3 ) + ( x + 3 ) = ( x + 3 )( x + 1 )

b) = x² - 3x - 5x + 15 = x( x - 3 ) - 5( x - 3 ) = ( x - 3 )( x - 5 )

c) = x² - 2x + 4x - 8 = x( x - 2 ) + 4( x - 2 ) = ( x - 2 )( x + 4 )

d) = x² - 4x + 3x - 12 = x( x - 4 ) + 3( x - 4 ) = ( x - 4 )( x + 3 )

e) = 4x² - 2x + 6x - 3 = 2x( 2x - 1 ) + 3( 2x - 1 ) = ( 2x - 1 )( 2x + 3 )

Answer 4

Trả lời:

a, x² + 4x + 3 = x² + 3x + x + 3 = x ( x + 3 ) + ( x + 3 ) = ( x + 3 )( x + 1 )

b, x² - 8x + 15 = x² - 3x - 5x + 15 = x ( x - 3 ) - 5 ( x - 3 ) = ( x - 3 )( x - 5 )

c, x² + 2x - 8 = x² + 4x - 2x - 8 = x ( x + 4 ) - 2 ( x + 4 ) = ( x + 4 )( x - 2 )

d, x² - x - 12 = x² - 4x + 3x - 12 = x ( x - 4 ) + 3 ( x - 4 ) = ( x - 4 )( x + 3 )

e, 4x² + 4x - 3 = 4x² - 2x + 6x - 3 = 2x ( 2x - 1 ) + 3 ( 2x - 1 ) = ( 2x - 1 )( 2x + 3 )