Упростите: а)(5x-3y)^2+30xy б)4x^4-2(x^4+1)^2
a) 25x^2-30xy+9y^2+30xy = 25x^2+9y^2
b) 4x^4-2(x^8+2x^4+1) = 4x^4- 2x^8-4x^4-2 = -2(x^8+1)