A = 3×4 – y4 – 5x2y – z2 B = 3×4 – 5x2y Tìm đa thức C biết : C + A = B 26/07/2021 Bởi Caroline A = 3×4 – y4 – 5x2y – z2 B = 3×4 – 5x2y Tìm đa thức C biết : C + A = B
Có C+A=B⇒C=B-A `⇒C=(3x^4-y^4-5x^2y-z^2)-(3x^4-5x^2y)` `⇔C=3x^4-y^4-5x^2y-z^2-3x^4+5x^2y` `⇔C=-y^4-z^2` $\text{Vậy C=$-y^{4}$-$z^{2}$}$ Bình luận
`C + A = B ⇒ C = B – A` `= (3x^4 – 5x^2y) – (3x^4 – y^4 – 5x^2y – z^2)` `= 3x^4 – 5x^2y – 3x^4 + y^4 + 5x^2y + z^2` `= (3x^4 – 3x^4) + (-5x^2y + 5 x^2y) + y^4 + z^2` `= y^4 + z^2` Bình luận
Có C+A=B⇒C=B-A
`⇒C=(3x^4-y^4-5x^2y-z^2)-(3x^4-5x^2y)`
`⇔C=3x^4-y^4-5x^2y-z^2-3x^4+5x^2y`
`⇔C=-y^4-z^2`
$\text{Vậy C=$-y^{4}$-$z^{2}$}$
`C + A = B ⇒ C = B – A`
`= (3x^4 – 5x^2y) – (3x^4 – y^4 – 5x^2y – z^2)`
`= 3x^4 – 5x^2y – 3x^4 + y^4 + 5x^2y + z^2`
`= (3x^4 – 3x^4) + (-5x^2y + 5 x^2y) + y^4 + z^2`
`= y^4 + z^2`