a=2j+5j

a = 7j

Explanation: Like terms combine, so 2j + 5j = (2 + 5) j = 7j. If j is the imaginary unit, this is 0 + 7i in standard a + bi form, and the magnitude is 7. If j is just a variable, it’s still 7j. Want to do more with this (e.g., convert to a + bi, compute magnitude, or in Python)?