We have to add and substract this complex numbers.
In this type of problems, where we have to add or substract complex numbers, we need to have the real and imaginary terms separated.
In this case, we already have all the terms as real or imaginary.
Then, we can group the real terms on one side and the imaginary terms on the other side and simplify them. We can do it like this:
[tex]\begin{gathered} (7-2i)-(-1-4i)+3 \\ 7-2i+1+4i+3 \\ (7+1+3)+(-2i+4i) \\ 11+2i \end{gathered}[/tex]Answer: 11 + 2i