Find the missing number help me plz before friday

Damon makes 20 cups of lemonade by mixing lemon juice and water. the ratio of lemon juice to water is shown in the tape diagram. lemon juice\text{lemon juice} lemon juice water\text{water} water how much lemon juice did damon use in the lemonade? cups

(60 points) explain this in detail

Factor and solve to find roots x squared -x - 90 =0