(u+4)cubed + 80=0

To solve the equation (u+4)³ + 80 = 0, we need to find the value of u that satisfies the equation. Here's how you can do it step by step:

1. Start by subtracting 80 from both sides of the equation to isolate the cubed term:
(u+4)³ = -80

2. Take the cube root of both sides to get rid of the exponent:
∛((u+4)³) = ∛(-80)

3. Simplify the cube root on the left side:
u+4 = ∛(-80)

4. Since we have a cube root of a negative number, we can express it in terms of complex numbers. The cube root of -80 can be written as -4∛5 (approximately -10.79).

5. Subtract 4 from both sides to isolate u:
u = -4 - 10.79

6. Finally, calculate the value of u:
u ≈ -14.79

Therefore, the approximate solution to the equation (u+4)³ + 80 = 0 is u ≈ -14.79.