Answer:
c
Step-by-step explanation:
10 percent of 11.50 is 1.15. Subtract that from 11.50 and you would get 10.35. The sale price would be $10.35
The slope is 0 and the y-intercept is (0,18)
For the units positions of all numbers we have:

From this we can conclude that total sum of these three numbers is 14. Number 1 we carry to next step. So we have:

For the tens positions of all numbers we have:

The extra number 1 on left side comes from the carry from last step. Similar to ones position we know that total sum is 11.

Now we insert x and z to find out y:

Now we need to find out the product of these three numbers: