Do you use the Pythagorean theorem and if so can you show me the process?

Find the number of real number solutions for the equation. x2 + 5x + 7 = 0 0 cannot be determined 1 2

Jessica is organizing a guided tour of the rain forest. the average profit per person that the touring company makes is given by the rational expression 18x+35/x, where x is the number of people going on the tour. what does the numerator of this rational expression represents?

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?