Here's the equation: 0.90(5.99) + 0.04(0.9(5.99)) We can simplify this: 0.90(5.99) + 0.036(5.99) 5.391 + 0.21564 5.60664 We can round: It will cost about $5.61
if you were to be solving for be you it will need to be an equation in order to be able to be solved but in this format it is nearly impossible to obtain an answer.