Final answer:
Using the quadratic formula, we find two solutions for t: t = 10 and t = -20 from the equation t² + 10t - 200 = 0. Since time can't be negative, the exact solution is t = 10 seconds.
Step-by-step explanation:
To solve for the time t using the quadratic formula, we will rearrange the equation to set it equal to zero, and then apply the formula. The quadratic formula is:
-b ± √(b² - 4ac) / (2a)
For the equation t² + 10t - 200 = 0, we identify a = 1, b = 10, and c = -200. Plugging these values into the quadratic formula, we get:
t = (-10 ± √((10)² - 4(1)(-200)))/(2(1))
This simplifies to:
t = (-10 ± √(100 + 800))/2
t = (-10 ± √900)/2
t = (-10 ± 30)/2
Yielding two solutions for t: t = (20/2) or t = (-40/2), which simplifies to t = 10 and t = -20. Since time cannot be negative, we discard t = -20 and keep t = 10 as the exact solution.