x² + 10x = 26
x² + 10x + 25 = 26 + 25
x² + 5x + 5x + 25 = 51
x(x) + x(5) + 5(x) + 5(5) = 51
x(x + 5) + 5(x + 5) = 51
(x + 5)(x + 5) = 51
(x + 5)² = 51
x + 5 = ±√(51)
- 5 - 5
x = -5 ± √(51)
x = -5 + √(51) or x = -5 - √(51)
I believe the answer is N+14=72
The x coordinate of the vertex will be the average of the two zeros, here -3 and 5, so x=(-3+5)/2 = 1, f(1)=(1+3)(1-5) = -16.
Answer: (1, -16)
Let's do it some other ways. How about completing the square to turn f in to vertex form?
f(x) = (x+3)(x-5) = x² - 2x - 15 = (x² - 2x + 1) - 1 - 15 = (x-1)² - 16
and now we can read off (1, -16) as the vertex.
The other method is the vertex is x= - b/2a = - (-2)/2(1) = 1.
Three methods, same answer. Good.
Answer:
1.5 hours
Step-by-step explanation:
using the relationship between distance/ speed / time
distance = speed × time
speed = 
= 
= 62 mph
travelling at this rate then
time = 
= 
= 1.5 hours
