Question

Упростите выражение: a) (3m-a)(a+ 3m) - (2a+m)(3а-м); (x-4y)(x+3y)-(x-3y)(3y+x). б)​

Answer 1

Ответ: -10y^2 + 3yx

Объяснение:

(3m - a)(a + 3m) - (2a + m)(3a - m)

= 3m*a + 9m^2 - a^2 - 3ma - 6am + am - 6a^2 + 2am + m^2

= 9m^2 - a^2 - 9a^2 + 5am + m^2

= 9m^2 - 10a^2 + 5am + m^2

(x - 4y)(x + 3y) - (x - 3y)(3y + x)

= x^2 - 4xy + 3xy - 12y^2 - 3xy + 9y^2 + 3yx - x^2 - 9y^2 - 3xy

= -10y^2 + 3yx

Answer 2

a) (3m-a)(a+3m) - (2a+m)(3a-m) =

= 3ma + 9m^2 - a^2 - 3am - 2a^2 - 3am + m^2 = -a^2 - 2a^2 + 3ma - 3am + 9m^2 + m^2 =

= -3a^2 + 6ma + 10m^2.

б) (x-4y)(x+3y)-(x-3y)(3y+x) =

= x^2 - 4xy + 3xy - 12y^2 - 3xy - x*3y + 12y^2 + x*3y =

=x^2 - 12y^2.