367.
а) (a+b)^2+(a-b)^2
a^2+2ab+b^2+a^2-2ab+b^2=a^2+a^2+b^2+b^2=2a^2+2b^2=2*(-2)^2+2*2^2=2*4+2*4=16
б) (x+y)^2-(x-y)^2
x^2+2xy+y^2-x^2-2xy+y^2=2y^2=2*(-0.5)^2=2*2.5=5
в) (a+0.5b)^2-(0.5a+b)^2
a^2+ab+2.5b^2-2.5a^2-ab+b^2=a^2+2.5b^2-2.5a^2+b^2=ab(a+2.5b-2.5a+b)=-6(3-5-7.5-2)=-6*11.5=69