Tìm đa thức N biết: ( $3$$x$$y$ – $4$$y^{2}$ ) – $N$ = $x^{2}$ – $7$$x$$y$ + $8$$y^{2}$ 24/08/2021 Bởi Bella Tìm đa thức N biết: ( $3$$x$$y$ – $4$$y^{2}$ ) – $N$ = $x^{2}$ – $7$$x$$y$ + $8$$y^{2}$
( 3xy – 4y² ) – N = x² – 7xy + 8y² N = ( 3xy – 4y² ) – ( x² – 7xy + 8y² ) N = 3xy – 4y² – x² +7xy -8y² N = ( 3xy + 7xy ) + ( -4y² – 8y² ) -x² N = 10xy – 12y² – x² Bình luận
Ta có: `(3xy-4y^2) – N = x^2 – 7xy + 8y^2` `N = (3xy-4y^2)-(x^2-7xy+8y^2)` `N=(3xy+7xy)-(4y^2+8y^2)-x^2` `N=10xy-12y^2-x^2` Bình luận
( 3xy – 4y² ) – N = x² – 7xy + 8y²
N = ( 3xy – 4y² ) – ( x² – 7xy + 8y² )
N = 3xy – 4y² – x² +7xy -8y²
N = ( 3xy + 7xy ) + ( -4y² – 8y² ) -x²
N = 10xy – 12y² – x²
Ta có: `(3xy-4y^2) – N = x^2 – 7xy + 8y^2`
`N = (3xy-4y^2)-(x^2-7xy+8y^2)`
`N=(3xy+7xy)-(4y^2+8y^2)-x^2`
`N=10xy-12y^2-x^2`