(5x-0.2)^2 = (25x^2 - 25x0.2 + 0.2^2) = 25x^2 - 2x + 0.04
(-2a+7b)^2 = (-2a)^2 + 2(-2a)(7b) + (7b)^2 = 4a^2 - 28ab + 49b^2
(a^3 + b^4)^2 = (a^3)^2 + 2a^3b^4 + (b^4)^2 = a^6 + 2a^3b^4 + b^8
(5x-0.2)^2 = (25x^2 - 25x0.2 + 0.2^2) = 25x^2 - 2x + 0.04
(-2a+7b)^2 = (-2a)^2 + 2(-2a)(7b) + (7b)^2 = 4a^2 - 28ab + 49b^2
(a^3 + b^4)^2 = (a^3)^2 + 2a^3b^4 + (b^4)^2 = a^6 + 2a^3b^4 + b^8