solve for u

4u²+20u=-25

To solve for u, first get all terms on one side of the equation:

4u² + 20u + 25 = 0

Now, try factoring or using the quadratic formula to solve for u. In this case, the equation does not seem to be factorable easily, so we can use the quadratic formula:

u = (-b ± √(b² - 4ac)) / 2a

In this equation, a = 4, b = 20, and c = 25. Plug these values into the formula:

u = (-20 ± √((20)² - 4*4*25)) / 2*4
u = (-20 ± √(400 - 400)) / 8
u = (-20 ± √0) / 8
u = -20 / 8
u = -2.5

Therefore, the solution for u is u = -2.5.