Evalute A = -1^2 + 2^2 - 3^2 + 4^2 - ..... + 2015^2 - 2016^2

1.Evalute A=-1^2 +2^2-3^2+4^2-..........+2015^2-2016^2
2.The equation expresses the statement :12 less than the product of 3 and b is 9
3.If ab=32,a-c=3 and 2b=16 then a+b+c=?
4.K=(2x+y)^2-(2y+x)2.If x^2-y^2=1 then K=.....
5.If 2y^3-5x=0 then 5x-2y^2+1=......
6.a+b+c+0 and abc=12.Evalute a^3+b^3+c^3