Câu hỏi của Nguyễn Thành Đạt

Question

Tìm đa thức M;N biết

a) M+(5$x^2$-2xy)=6$^{x^2}$+9xy-$^{y^2}$

b) (3xy-4$^{y^2}$)-N=$^{x^2}$-7xy+8$^{y^2}$

Fa Châu De · Accepted Answer

$a,$ $M+\left(5x^2-2xy\right)=6x^2+9xy-y^2$

$M=\left(6x^2+9xy-y^2\right)-\left(5x^2-2xy\right)$

$M=6x^2+9xy-y^2-5x^2+2xy$

$M=\left(6x^2-5x^2\right)+\left(9xy+2xy\right)-y^2$

$M=x^2+11xy-y^2$Câu trả lời: $a,$ $M+\left(5x^2-2xy\right)=6x^2+9xy-y^2$

$M=\left(6x^2+9xy-y^2\right)-\left(5x^2-2xy\right)$

$M=6x^2+9xy-y^2-5x^2+2xy$

$M=\left(6x^2-5x^2\right)+\left(9xy+2xy\right)-y^2$

$M=x^2+11xy-y^2$

Fa Châu De · Answer

$b,$ $\left(3xy-4y^2\right)-N=x^2-7xy+8y^2$

$N=\left(3xy-4y^2\right)-\left(x^2-7xy+8x^2\right)$

$N=3xy-4y^2-x^2+7xy-8x^2$

$N=\left(3xy+7xy\right)-4y^2-\left(x^2-8x^2\right)$

$N=10xy-4y^2+7x^2$Câu trả lời: $b,$ $\left(3xy-4y^2\right)-N=x^2-7xy+8y^2$

$N=\left(3xy-4y^2\right)-\left(x^2-7xy+8x^2\right)$

$N=3xy-4y^2-x^2+7xy-8x^2$

$N=\left(3xy+7xy\right)-4y^2-\left(x^2-8x^2\right)$

$N=10xy-4y^2+7x^2$

B.Thị Anh Thơ · Answer

b, (3xy-4y2 )-N=x2 -7xy+8y2

=> N= (x2 -7xy+8y2 ) -(3xy-4y2)

=> N= (x2 -7xy+8y2 -3xy+4y2)

=> N= x2 -4xy+12y2Câu trả lời: b, (3xy-4y2 )-N=x2 -7xy+8y2

=> N= (x2 -7xy+8y2 ) -(3xy-4y2)

=> N= (x2 -7xy+8y2 -3xy+4y2)

=> N= x2 -4xy+12y2

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