1). 1. (у-4)^2
y^2-2y x 4+4^2
y^2-8y+16
2. (7x+a)^2
(7x)^2+2 x 7xa+a^2
49x^2+14ax+a^2
3. (5c-1) x (5c+1)
(5c)^2 - 1^2
25c^2-1
4. (3a+2b)(3a-2b)
(3a)^2-(2b)^2
9a^2-4b^2
2). 1. x^2-49
x^2-7^2
(x-7)(x+7)
2. 25x^2-10xy+y^2
5^2x^2-2 x 5x x y + y^2
(5x)^2 - 2 x 5x x y + y^2
(5x-y)^2
3). 1. 4x^2y^2-9a^4
2^2x^2y^2-3^2a^2x2
(2xy)^2-3^2 x (a^2)^2
(2xy)^2-(3a^2)^2
(2xy-3a^2) x (2xy+3a^2)
2. 25a^2-(a+3)^2
(5a-(a+3)) x (5a+(a+3))
(5a-a-3) x (5a+a+3)
(4a-3) x (6a+3)
(4a-3) x 3(2a+1)
3(4a-3) x (2a+1)
4). 1. (y^2-2a) x (y^2+2a)
(y^2-2a) x (y^2+2a)
y^4-4a^2
2. (3x^2+x)^2
(3x^2)^2+2 x 3x^2 x x+x^2
9x^4+6x^3+x^2
