Find the equation of the line that contains the given point and is perpendicular to the given line. Write the equation in slope-intercept form, if possible (35,5); y=- 7x-7

What is the missing step in this proof ?

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?

Similarly fie each expression 18,19,20