I'm not following. What's the question?
Answer:

Step-by-step explanation:
Given

Required:
Simplify
We start by opening the bracket


Collect Like Terms

Hence, the equivalent expression is 
Answer:
4
Step-by-step explanation:
b+12 =16
-12. -12
b = 4
hope this helps
Answer:
The linear function that discribes the size of the population in function of the t in years is p = 700t - 1,397,300
Step-by-step explanation:
A linear function is defined by a line, so in order to determine the linear function we can use the two points that were given to us to create a line equation and use that as our linear function. The points given to us were (2009; 9000) and (2014; 12500), in this case the year is our value of "x" and the size of the population is our value of "y". The first step is to find the slope of the line which is given by:
m = (y2 - y1)/(x2 - x1)
m = (12500 -9000)/(2014 - 2009) = 3500/5 = 700
Then we can use the slope and the first point to build the equation:
p - 9000 = 700*(t - 2009)
p = 700t - 1406300 + 9000
p = 700t - 1397300
Answer:
For this scenario, I used the elimination method. Organize the equations, so it's easier to subtract from each other. My x-variable will represent the number of hot dogs and my y-variable will represent the number of sodas.
3x+2y=213
x + y =87
We need to make sure one of the monomials are alike in each equation, so we can eliminate a variable. Distribute 3 to each number/variable in the second equation.
3x+2y=213
3(x+y=87) --> 3x+3y=261
Now we can eliminate x.
3x+2y=213
- 3x+3y=261
----------------------
-y=-48
Divide -1 to both sides to get y=48. So, you sold 48 cans of soda. Now, we can find the number of hot dogs by substituting 48 into the second equation to get x+48=87. Subtract 48 to both sides to result with x=39. So, you sold 39 hot dogs.