✓ Got It?

3. 1. You row upstream at a speed of 2 mi/h. You travel the same distance downstream at a speed of 5 mi/h. What would be your rowing speed in still water? What is the speed of the current?
   2. Reasoning Suppose your rowing speed in still water is 3 mi/h and the speed of the current is 4 mi/h. What happens when you try to row upstream?

✓ Lesson Check

Do you know HOW?

1. Newsletters Printing a newsletter costs $1.50 per copy plus $450 in printer's fees. The copies are sold for $3 each. How many copies of the newsletter must be sold to break even?
2. Jewelry A metal alloy is a metal made by blending 2 or more types of metal. A jeweler has supplies of two metal alloys. One alloy is 30% gold and the other is 10% gold. How much of each alloy should the jeweler combine to create 4 kg of an alloy containing 15% gold?

3. Flying With a tailwind, a bird flew at a ground speed of 3 mi/h. Flying the same path against the same wind, the bird travels at a ground speed of 1.5 mi/h. What is the bird's air speed? What is the wind speed?

   Do you UNDERSTAND?

4. Vocabulary What is the relationship between income and expenses before a break-even point is reached? What is the relationship between income and expenses after a break-even point is reached?

5. Reasoning Which method would you use to solve the following system? Explain.

   3 x + 2 y = 9 3 x plus 2 y equals 9

   − 2 x + 3 y = 5 negative 2 x plus 3 y equals 5

6. Reasoning One brand of cranberry-apple drink is 15% cranberry juice. Another brand is 40% cranberry juice. You would like to combine the brands to make a drink that is 25% cranberry juice. Without calculating, which brand of juice will you need more of to make your drink? Explain.