5. Andre makes a trip to Mexico. He exchanges some dollars for pesos at a rate of 20 pesos per dollar. While in Mexico, he spends 9000 pesos. When he returns, he exchanges his pesos for dollars (still at
20 pesos per dollar). He gets back to the amount he started with. Find how many dollars Andre
exchanged for pesos and explain your reasoning. If you get stuck, try writing an equation representing
Andre's trip using a variable for the number of dollars he exchanged.