If you divide 156 by 12 it'll give you 13, so there are 13 in each group
That night he got caught in the rain and exploded
1/9
Here's the proper explanation:
Since the vertex is (2,-1), the original equation will look like this: y=a*(x-2)^2-1
When the substitution happens we get to this:
0=a*(5-2)^2-1 then 1=a*(5-2)^2 -> 1=a*9
So, a=1/9! Written in another form:
1/9x^2-4/9x+4/9-1
Hope could help :)
So what you have is this:
y = -65x + 1000
this is a form of

,
where

is the slope and

is the y-intercept of the linear relationship.
so, -65 is

and 1000 is the

It should be a piece of cake from there :D
The fraction form is 125/343
the decimal form is 0.36