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:20%
Step-by-step explanation:
Percentage decrease=(65.50-52.40)/65.50 x 100
Percentage decrease=13.1/65.50 x 100
Percentage decrease=0.2 x 100
Percentage decrease=0.2 x100
Percentage decrease=20
Step 6. Check the answer in the problem and make sure it makes sense.
Yes, 75+0.25\left(500\right)=200.
Step 7. Write a sentence that answers the question. Sergio and Lizeth can travel 500 miles and still stay on budget.
Taleisha’s phone plan costs her ?28.80 a month plus ?0.20 per text message. How many text messages can she use and keep her monthly phone bill no more than ?50?
