Answer:
Step-by-step explanation:
9. discount is 9 dollars. sale price is 36 dollars
10. discount is 135 dollars sale price is 315
11. discount is 7.20 dollars, sale price is 41.80
12. discount is 37.50. sale price is 112.50
13. discount is 590. sale price is 870
14. discount is 42. sales price is 42
15. discount is 32.50. sales price is 292.50
16. discount is 29.75. sales price is 56.25
17. The similarities is that there's a difference in the original price, usually in a percentage. The difference is that a markup is a increase whereas a discount is a decrease
Answer:

________

Step-by-step explanation:
Given

Line up the numbers

Multiply the top number by the bottom number one digit at a time starting with the ones digit left(from right to left right)
Multiply the top number by the bolded digit of the bottom number

Multiply the bold numbers: 1×4=4

Multiply the bold numbers: 2×4=8

Multiply the top number by the bolded digit of the bottom number

Multiply the bold numbers: 1×1=1

Multiply the bold numbers: 2×1=2

Add the rows to get the answer. For simplicity, fill in trailing zeros.

adding portion

Add the digits of the right-most column: 4+0=4

Add the digits of the right-most column: 8+1=9

Add the digits of the right-most column: 0+2=2

Therefore,

________

It can be a fraction, a decimal, a mixed number, or any irrational number.