F(x)=-x^2+8x-20 find the min/max value

Write the fraction or mixed number and the decimal shown by the model

Math each whole number with a rational, exponential expression

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?