1. a) (a +4)² =a² +8a +16
b) (3y -c)² =9y² -6yc +c²
в) (2a -5)(2a +5) =4a² -25
г) (x2 +y)(x2 -y) =4x² -y²
2. a) 0.36-c² =(0.6-c)(0.6+c)
b) a² +10a +25 =(a +5)² = (a+5)(a+5)
3.а где значение b=?
(a -2b)² +4b(a-b)=a²- 4ab +b² +4ab -4b² =a² -3b² = (0.12)² -3b² =3(0.04 -b²) =
=3(0.2 -b)(0.2 +b)
4. a) 3(1 +2xy)(1 -2xy) =3(1 - 4x²y²) =3 -12x²y²
b) (a +b)² -(a -b)² =a² +2ab +b² -a² +2ab -b² =4ab
в) (x² -y^3)² =x^4 -2x²y^3 + y^6