a, `M = 6x^6y + 1/3x^4y^3 - y^7 - 4x^4y^3 + 10 - 5x^6y + 2y^7 - 2,5`
`M = ( 6x^6y - 5x^6y ) + ( 1/3x^4y^3 - 4x^4y^3 ) + ( - y^7 + 2y^7 ) + ( 10 - 2,5 )`
`M = x^6y + ( -11/3x^4y^8 ) + y^7 + 7,5`
`Bậc` `:` `7`
b, `Thay` `x = -1` `y = 1` `vào` `đa` `thức,` `ta` `được` `:`
`M = ( - 1 )^6 . 1 + -11/3 . ( -1 )^4 . 1^8 + 1^7 + 7,5`
`M = 1 . 1 + -11/3 . 1 . 1 + 1 + 7,5`
`M = 1 + -11/3 + 1 + 7,5`
`M = 3/3 + -11/3 + 3/3 + 7,5`
`M = -5/3 + 7,5`
`M = -1,6 + 7,5`
`M = 5,9`
HỌC TỐT NHA !
#NOCOPY
