There are 3 complex numbers a + bi, c + di, and e + fi. If b = 7, e = -a - c, and the sum of the numbers is -3i, find d + f.
$(a+c+e)+(b+d+f)i=-3i\implies (a+c-a-c)+(7+d+f)i=-3i\implies (d+f+7)i=-3i\implies d+f+7=-3\impies d+f=-\boxed{-10}$.
+605 
