Substance A decomposes at a rate proportional to the amount of A present. a) Write an equation relating A to the amount left of an initial amount Upper A 0 after time t. b) It is found that 18 lb of A will reduce to 9 lb in 4.2 hr. After how long will there be only 1 lb left?

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.