Hello!
Let's write some important information contained in the exercise:
• hotdogs: $2.59 (,x,)
,
• hamburgers: $5.29 (,y,)
He needs 11 packages. Let's write it:
• x + y = 11
He spent a total of $39.29. We can write it as:
• 2.59x + 5.29y = 39.29
Now, let's solve these two equations as a linear system:

First, let's isolate x in equation A:

Now, we will replace where's x by 11-y in equation B:

As I called the hamburgers as 'y', we know that he bought 4 packages of hamburgers.
Answer:
x = 24
y = 19
Step-by-step explanation:
In this case, since one equation is in the form of x=, substitution would be best for this problem. Simply plug in 4y + 8 in place of x in the second equation, solve for y, then plug that value into the first equation to find x.
I got 6 units^2. So the answer is the second choice. ab/2 = 3*4/2 = 6.