Answer:
Step-by-step explanation:
Given equation of the quadratic function is,
y = x² + 5x - 7
Convert this equation into vertex form,
y = x² + 2(2.5x) - 7
= x² + 2(2.5x) + (2.5)² - (2.5)² - 7
= (x + 2.5)²- 6.25 - 7
= (x + 2.5)² - 13.25
Therefore, vertex of the function is → (-2.5, -13.25)
For the solutions,
y = 0
(x + 2.5)² - 13.25 = 0
x = (±√13.25) - 2.5
x = (±3.64) - 2.5
x = 1.14, -6.14
Solutions → (-6.14, 0) and (1.14, 0)
The percentage of vehicles passing through this construction zone that are traveling at a speed of 50 and 57 miles per hour
