Toán Lớp 8: Phân tích đa thức thành nhân tử: a, (2x+1) ²+2.(2x+1) b, x.(2x+y)+y.(2x+y) c, y.(x+y)-x-y d, 2y.(x-y) ²+x.(y-x) ² Giúp mik nha mng~

Question

Toán Lớp 8:  Phân tích đa thức thành nhân tử: a, (2x+1) ²+2.(2x+1) b, x.(2x+y)+y.(2x+y) c, y.(x+y)-x-y d, 2y.(x-y) ²+x.(y-x) ² Giúp mik nha mng~

kimnguenoanh · Answer

Ch&uacute;c bạn     hok tốt!!      cho mik xin ctlhn nha   a)   ( 2x + 1 )&sup2; + 2.( 2x + 1 )   = ( 2x + 1 ) . ( 2x + 1 ) + 2 . ( 2x + 1 )   = ( 2x + 1 ) ( 2x + 3 )   = 4x&sup2; + 6x + 2x + 3   = 4x&sup2; + 8x + 3   b)   x.(2x + y) + y.(2x + y)   = ( x + y ) ( 2x + y )   = 2x&sup2; + xy + 2xy + y&sup2;   = 2x&sup2; + 3xy + y&sup2;   c)   y.(x - y) - x - y   = y(x - y) - x + y - 2y   = y(x - y) - (x - y) - 2y   = ( y - 1 ) (x - y) - 2y   = xy - y&sup2; - x + y - 2y   =xy - y&sup2; - x - y   d)   2y ( x - y )&sup2; + x ( y - x )&sup2;   = 2y ( x&sup2; -2xy + y&sup2; ) + x ( y&sup2; - 2xy + x&sup2; )   = 2x&sup2;y - 4xy&sup2; + 2y&sup3; + xy&sup2; - 2x&sup2;y + x&sup3;   = ( 2x&sup2;y - 2x&sup2;y ) - ( 4xy&sup2; - xy&sup2; ) + x&sup3; + 2y&sup3;   = - 3xy&sup2; + x&sup3; + 2y&sup3;

cobebongdem · Answer

a) $ (2x+1)&sup2;+2.(2x+1)  = (2x+1)(2x+1)+2.(2x+1) = (2x+1)(2x+3)$     b) , $x.(2x+y)+y.(2x+y) = (x+y)(2x+y)$     c)$ y.(x+y)-x-y = y(x+y) - (x+y) = (y-1)(x+y)$     d)$2y.(x-y)&sup2;+x.(y-x)&sup2; = 2y.(x-y)&sup2;+x.(x-y)&sup2; = (2y+x)(x-y)&sup2;$