What are the solutions of −4x2 – 72 = 0?

Sure, let's solve the equation step by step:

1. First, let's rewrite the equation: -4x^2 - 72 = 0

2. We can add 72 to both sides to isolate the term with the variable: -4x^2 = 72

3. Then, divide both sides by -4 to solve for x^2: x^2 = -18

4. To solve for x, we take the square root of both sides. However, the square root of a negative number is not a real number. It's an imaginary number. So, we can say that x = sqrt(-18), which can be simplified to x = ±3i√2.

So, the solutions to the equation -4x^2 - 72 = 0 are x = 3i√2 and x = -3i√2.