First think out the equation, once you've done that multiply 3 by 25 to get 75
If both lines are same length then 7+3=10
Well she starts with $7 and gets $1 the first time by selling it one dollar more than she bought it for. Then she loses nine dollars so that's $1-$9 which is -$8. Then she makes $10. So that would be -8+10 which is 2. So she made $2 profit.
