so what you do is keep change chang for any integer problem.
so if it is 4+-45, keep change change
keep the first number, which is 4
change the addition sign to a negative sign because you are changing it to its opposite.
and last change the negative sign to a posotive sign. because it is its opposite.
so you end up with 4-+45.
so basiclly it is 4-45
which is -41.
hope i helped.
:)