Final answer:
The expression equivalent to 1+5i-5 is -4+5i because we subtract the real numbers (1-5) to get -4, and the imaginary term 5i remains unchanged.
Step-by-step explanation:
The student is asking for the expression equivalent to 1+5i-5. To simplify this expression, we subtract like terms. The real number 5 subtracted from 1 will be 1 - 5, which equals -4. This leaves us with the imaginary part, 5i, unchanged because there is no other imaginary term to combine it with. Thus, the expression simplifies to -4 + 5i.
One way to think of this is similar to the example provided, where 5 - (+3) = 2. The subtraction of real numbers changes the sign of the term being subtracted, which is what happens with the 1 - 5 in the original expression. The imaginary part behaves the same way, except there are no additional imaginary numbers to combine with, so 5i remains as is.