Rút gọn 2x ( 6x – 5 ) + 10x ( x – 3 )^2 + ( x + 3 ) ( x+ 2) Phân tích 4x^2 – 12x (x – y) ^2 – 100 x^2 – y^2 + 5x + 5y

2 bình luận về “Rút gọn 2x ( 6x – 5 ) + 10x ( x – 3 )^2 + ( x + 3 ) ( x+ 2) Phân tích 4x^2 – 12x (x – y) ^2 – 100 x^2 – y^2 + 5x + 5y”

1. Rút gọn:

   2x(6x-5)+10x

   =12x^2-10x+10x

   =12x^2

   (x-3)^2+(x+3)(x+2)

   =x^2+6x+9+(x^2+2x+3x+6)

   =x^2+6x+9+x^2+5x+6

   =2x^2+11x+15

   PTĐTTNT:

   4x^2-12x

   =4x(4x^2:4x-12x:4x)

   =4x(x-3)

   (x-y)^2-100

   =(x-y)^2-10^2

   =(x-y-10)(x-y+10)

   x^2-y^2+5x+5y

   =(x^2-y^2)+(5x+5y)

   =(x-y)(x+y)+5(x+y)

   =(x-y+5)(x+y)

   Trả lời
2. Rút gọn 

   2x ( 6x – 5 ) + 10x

   = 12x² – 10x + 10x

   = 12x²

   ( x – 3 )² + ( x + 3 ) ( x + 2 )

   = x² – 6x +9 + x² + 5x + 6

   = 2x² + 11x + 15

   Phân tích 

   4x² – 12x

   = 4x ( x – 3 )

   ( x – y )² – 100

   = ( x – y )² – 10²

   = ( x – y – 10 ) ( x  – y + 10 )

   x² – y² + 5x + 5y

   = ( x – y ) ( x + y ) + 5 ( x + y )

   = ( x + y ) ( x – y + 5 )

    

   Trả lời