I need this pleassse!
f(x)=x^{2}-x
if f(x)= -3

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

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6

If f(x)=3 over x+2 - square root x-3 then f(7)=