Y=mx+b to slove 34y×2

Me find the measure to side a and the process to solve the problem you appreciate it : )

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

Sally deposited money into a savings account paying 4% simple interest per year. the first year, she earned $75 in interest. how much interest will she earn during the following year?