Solve the equation: 4x^2 + 100 = 0

Question

Here is my work:
4x^2 + 100 = 0
- 100 - 100
4x^2 =0
/4 /4
x = -5 or 5.
Did I do this correctly?

Answer 1

Not quite. You know that x^2 is always positive. How do you add two positive numbers to get zero?

4x^2 + 100 = 0
x^2 + 25 = 0
x^2 = -25
x = ±5i, not ±5