Câu hỏi của Miko

Question

Phá ngoặc rồi thu gọn

a) $5x^2-\left(3y^2+5x^2\right)-\left(4x^2-3y^2\right)$

b) $2x\left(x^2-y^2\right)-3x\left(2x^2+3y^2\right)$

Aki Tsuki · Accepted Answer

a/ $5x^2-\left(3y^2+5x^2\right)-\left(4x^2-3y^2\right)$

$=5x^2-3y^2-5x^2-4x^2+3y^2$

$=\left(5x^2-5x^2-4x^2\right)+\left(3y^2-3y^2\right)$

$=-4x^2$

b/ $2x\left(x^2-y^2\right)-3x\left(2x^2+3y^2\right)$

$=2x^3-2xy^2-6x^3-9xy^2$

$=\left(2x^3-6x^3\right)+\left(-2xy^2-9xy^2\right)$

$=-4x^3-11xy^2$Câu trả lời: a/ $5x^2-\left(3y^2+5x^2\right)-\left(4x^2-3y^2\right)$

$=5x^2-3y^2-5x^2-4x^2+3y^2$

$=\left(5x^2-5x^2-4x^2\right)+\left(3y^2-3y^2\right)$

$=-4x^2$

b/ $2x\left(x^2-y^2\right)-3x\left(2x^2+3y^2\right)$

$=2x^3-2xy^2-6x^3-9xy^2$

$=\left(2x^3-6x^3\right)+\left(-2xy^2-9xy^2\right)$

$=-4x^3-11xy^2$

Trần Thị Huệ · Answer

a)5x^2 - (3y^2 + 5x^2 ) - (4x^2 - 3y^2)

=5x^2 - 3y^2 - 5x^2 - 4x^2 + 3y^2

=5x^2 - 5x^2 - 4x^2 - 3y^2 + 3y^2

=-4x^2

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

=2x^3 - 2xy^2 - 6x^3 - 9xy^2

=2x^3 - 6x^3 -2xy^2 -9xy^2

=-4xy^3 - 11xy^2Câu trả lời: a)5x^2 - (3y^2 + 5x^2 ) - (4x^2 - 3y^2)