13, because 78 postcards divided by 6 cards per board = 13 poster boards
Hot Dog Stand
Let
C--------> total cost of the hot dog
x-------> is the number of toppings
we know that

where
The slope of the linear equation is equal to 
The y-coordinate of the y-intercept of the linear function is equal to 
That means -------> This is the cost of the hot dog without topping
Hamburgers Stand
Let
C--------> total cost of the hamburger
x-------> is the number of toppings
we know that

where
The slope of the linear equation is equal to 
The y-coordinate of the y-intercept of the linear function is equal to 
That means -------> This is the cost of the hamburger without topping
therefore
<u>the answer is</u>
The linear equation of the hamburger cost is equal to

The total square footage 2,070 Sq Ft
Answer:
Step-by-step explanation:
f(x) = x^2 + 4x + 4
f(x + a) = (x + a)^2 + 4(x + a) + 4
f(x + a) = x^2 + 2ax + a^2 + 4x + 4a + 4 Now combine like terms and use the distributive property.
f(x + a) = x^2 + (2a + 4)x + a^2 + 4a + 4
We are told that f(x + a) = x^2 - 6x + 9
So that means that
2a + 4 = - 6 Subtract 4 from both sides.
2a = - 6 - 4
2a = - 10 Divide by 2
a = - 10/2
a = - 5.
But you are not finished. You have to check the last part.
a^2 + 4x + 4 = 9
(a + 2)^2 = 9
Take the square root of both sides
sqrt(a+ 2)^2 = +/- 3
a+2 = 3
a = 1.
Does this work or is it extraneous? It is extraneous because it will not work for 2(a) + 4 = - 6
You get 6 = - 6 which is not correct. But you did give the second best answer.
a + 2 = - 3
a = - 3 - 2
a = - 5 which agrees with your previous answer.
===========
This is an extremely hard or tricky or sneaky problem. It takes a lot of conniving to get the right answer and 1 is not a left field answer. It just does not happen to be correct.
No they cannot because 3 is way to short