Question

Помогите пожалуйста. Даю 30 баллов.

Answer 1

1) а) (y-4)^2= y^2-8y+16
b) (7x + a)^2= 49x^2 + 14xa + a^2
c) (5c-1) (5c+1)= 25c^2 -1
d)(3a + 2b) (3a - 2b)= 9a^2 -4b^2
2) (a -9)^2 - (81 + a) = a^2 -18a +81 -81 - a = -18a^2
3) a) x^2 -49 = (x-7) (x+7)
b)25x^2 -10xy + y^2 = (5x -y)^2
4) (2-x)^2 - x (x+ 1,5)=4
4 - 4x^2 + x^2 - x^2 - 1,5x =4
5.5x=4-4
5.5x=0
бесконечно много корней .


5) (y^2- 2a)(2a +y^2)= y^4 -4a^2
b) (3x^2 +x) ^2= 9x^4 + 6x^3 + x^2
c)(2+m) (2-m) = 4- m^2

6) a) 4x^2 y^2 -9a^4 = (2xy - 3a^2) (2xy+ 3a^2)
b) 25a^2 - (a+3)^2 = 25 a^2 - a^2 -6a +9 = 24a^2 - 6a +9
c)27 m^3 +n^3 = (3m + n) ( 9m^2 - 3mn +n^2 )