The store cost .057 cents more.
The store is more expensive.
Answer:

Step-by-step explanation:
First, note that

And using the chain rule in one variable

Now remember that the chain rule in several variables sates that

Therefore the chain rule in several variables would look like this.

Answer:
x = 1
y = -2
Explanation:
First, solve for x by subtracting 7y from both sides of the first equation and then divide both sides by -5.
-5x + 7y = -19
-5x + 7y - 7y = -19 - 7y
-5x = -19 - 7y
-5x/ -5 = -19 - 7y/ -5
x = -19 - 7y/ -5
Next, substitute the value of x into the second equation and solve.
6 - (-19 - 7y)/ 5 - 2y = 10
- 6(-19 - 7y)/ 5 - 2y = 10
Then, solve for y
- 6(-19 - 7y)/ 5 - 2y = 10
-6(-19 - 7y) - 10y = 50
114 + 42y - 10y = 50
144 + 32y = 50
32y = 50 - 144
32y = -64
32y/ 32 = -64/ 32
y = -2
Finally, substitute the value of y into the x value we found earlier and solve
x = - 19 - 7y/ 5
x = - 19 - 7 • -2/ 5
x = 1