(2x^2-x+5)^2 = (2x^2-x+5)(2x^2-x+5)
= 4x^4 - 2x^3 + 10x^2 - 2x^3 + x^2 - 5x + 10x^2 - 5x + 25
= 4x^4 - 4x^3 + 21x^2 - 10x + 25