(3z²-5)(3z²+5)=9z^4-25;
(y+3)²=y²+6y+9;
(a-5)²=a²-10a+25;
(2b²-1)²=4b^4-4b²+1;
(5+3c²)²=9c^4+30c^2+25;
(c+2)(c²-c+4)=c^3+8;
(y-3)(y²+3y+9)=y^3-27.
3x³-2x³+7x-3-x³-x²+4x-7=2x³-3x²+11x-10
...........................
(1,2а-4)+(40-4,8а)=1,2а-4+40-4,8а=36-3,6а=3,6(10-а)