1. a) = -6x^4×y^7
b) =16a²b^6
v) (4x-2y)(5x+2y) =20x² +8xy -10xy -4y² =
=20x² -2xy -4y²
г) (x -2)(x +2) -(x -3)² =x² -4 -x² +6x -9 =
=6x -13
2. a) =3x(16x² -y²) =3x(4x -y)(4x +y)
b) =3(a² -6ab +9b²) =3(a -3b)²
v) =(x² -4y²) +(x -2y) =(x -2y)(x+2y) +(x -2y) =
=(x -2y)(x +2y +1)
3. 3x -5(2x -1) =3(3 -2x)
3x -10x +5 =9 -6x
-7x +6x =9 -5
-x =4
x =4