(c+2a^2) ^2=c^2+2c•2a^2+(2a^2) ^2=c^2+4a^2c+4a^2.
(b-a^2) ^2=b^2-2ba^2+(a^2) ^2=b^2-2a^2b+a^4.
(7c+a^2) ^2=(7c) ^2+2•7ac^2+(a^2) ^2=49c^2+14a^2c+a^4.
(x-5n^3) ^2=x^2-2x•5n^3+5(n^3) ^2=x^2-10n^3x+25n^6
