It costs 30 pesos to enter a currency exchange building. Once there, you can exchange 20 pesos for 1 dollar. How many pesos are required to get z dollars? (Write your answer as an expression)
Entry fees: 30 pesos; exchange rate: $1 = 20 pesos OR 1 PESO= 1/20 DOLLAR: This is a linear function of the form y = mx + b, where b is the entry fee, x the number of $ and y = z = amount of pesos: z= (1/20).x + 30