Bob is selling floral arrangements. each arrangement uses 1 vase and 15 tulips. each vase costs bob $4.00. let c be the total cost of the arrangement and t be the cost of 1 tulip. write an equation, in slope-intercept form, that represents the total cost of each arrangement to bob. use this equation to find out what the cost of the arrangement would be if each tulip costs bob $2.00.