greatest common factor=gcf
least common multule=lcm
with 12 and 16
factors of 12=2 times 2 times 3
factors of 16=2 times 2 times 2 times 2
greates common factor is 2 times 2=4
least common multiple means all factors combined minus repeats or 2 times 2 times 2 times 2 time 3=48
We have to express the ratio 1 : 3.5 in the form p:q where p and q are whole numbers.
Consider the ratio of 1 and 3.5,
1 : 3.5 = 
= 
Reducing the above fraction to its lowest form.
So, we get 
Therefore, the ratio 1 : 3.5 is expressed as 
where 2 and 7 are the whole numbers.
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.
