A peristaltic pump delivers a unit flow (Q1) of a highly viscous fluid. The network is depicted in Fig. P9.14. Every pipe section has the same length and diameter. The mass and mechanical energy balance can be simplified to obtain the flows in every pipe. Solve the following system of equations to obtain the flow in every stream. Q3 + 2Q4 - 2Q2 = 0
Q5 + 2Q6 - 2Q4 = 0
3Q7 - 2Q6 = 0
Q1 = Q2 + Q3
Q3 = Q4 + Q5
Q5 = Q6 + Q7

Paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each? 1. define a variable for the situation. 2. write an inequality that represents her profit. note: revenue is money coming in. cost is money going out. profit is the difference between the revenue and the cost. in other words: revenue - costs profit 3.using words, describe how many windows she must sell to have a profit of at least $48,000.