1) а)(y-4)^2= y^2-8y+16
б)(7x+a)^2= 49x^2+14xa+a^2
в) (5c-1)(5c+1)= 25c^2-1
г)(3a+2b)(3a-2b)= 9a^2-4b^2
2) а)x^2-49= (x-7)(x+7)
б)25x^2-10xy+y^2= (5x-y)^2
3) (2-x)^2 - x(x+1,5) = 4
4- 4x+ x^2 - x^2 -1,5x=4
-6,5x=0
x=0
4) а) (y^2-2a)(2a+y^2)= y^4-4a^2
б) (3x^2 +x)^2 = 9x^4+ 6x^3+ x^2
5) 9y^2-25=0
(3y-5)(3y+5)=0
1. 3y-5=0 3y=5 y=5/3
2. 3y+5=0 3y=-5 y= - 5/3