It has a minimum value at x = 3 and f(x) = 4
Vertex form is
f(x) = a(x - 3)^2 + 4 where a is some constant to be found
From the graph when x = 5 f(x) = 15, so
15 = a * 2^2 + 4
a = 15-4/4 = 11/4
so our equation is f(x) = 11/4(x - 3)^2 + 4
Easy I guess ..
I ll try to help ..
Here we go ..
The cards you have is N
The cards he has is n
<span>you have 3 times the number of cards he has
This means N=3n
</span><span> you only have 80 more football cards then he does
This means N=n+80
But we already know that N=3n
So 3n=n+80
which is 2n=80
n=40
So your friend has only 40 cards and you have 3*40= 120 cards
Best luck
Wise</span>
The goal of all algebra equations is to isolate the variable. In 3 step you should first make sure both variables are on the same side. To do that make sure you use the inverse.
For example:
6a + 9 = 3a + 15
because 3a is positive you're going to want to subtract it.
6a + 6 = 3a + 15
-3a -3a
_______________
3a + 6 = 15
Now it's a 2 step equation and you solve it on from there.