Robin has to go shopping for her brother's birthday.
She already bought "x" presents for him.
The next day, Robin bought "2" more presents for him just in time for his birthday.
When she got home and celebrated his birthday, her beother opened, in total, "9" presents.
--- What is the number of presents that Robin had originally purchased? ---
Answer:
1. Use a straightedge
2. Draw dots on the line to mark the starting point
3. Place the point of the compass on the point you made or was given
4. Extend the compass so that the pencil is on the 2nd point & make a an arc thru point B
5. Place the compass point on the starting point dot on the line and draw w/ the pencil to create an arc crossing the line.
The y intercept is going to be 10x
