consider the following situation: Mr. Richards wants to buy disposable masks for his family. Elure masks cost $1.50 and white masks cost $2.50. He has $45 to spend and wants to buy a total of 20 masks. 12. Define your variables and write an equation to represent the number of masks Richards is buying. 13. Using the same variables write an equation to represent the cost of the masks Richards is buying. 14. Choose either substitution or elimination and solve the system of equations you have created to determin many of each color Richards can buy. Show all of your steps.​