given that f(x,y) =30xy^2 for x-1<y<1-x and 0<x<1. find F(0.5,0.5)

i know that we need to do double integration and i tried to integration from -0.5 to (1-x) dy followed by integration from 0 to 0.5 dx..but my answer was wrong...

may i know what is wrong with my understanding of this question?

thanks!