- Airports A traveler is walking on a m oving walkway in an airport. The ^ See Problem 3.
traveler m u st w alk back on th e walkway to get a bag h e forgot. The traveler's
gro u n d sp eed is 2 f t / s against th e walkway an d 6 f t / s w ith th e walkway. W hat is
th e traveler’s sp eed off th e walkway? W hat is th e speed of th e m oving walkway? - Kayaking A kayaker p ad d les u p strea m from cam p to p h o to g rap h a w aterfall a n d
returns. The kayaker’s speed while traveling u p strea m a n d d ow nstream is show n
below. W hat is th e kayaker’s speed in still water? W hat is the sp ee d of th e current?
Money You have a jar of p en n ies an d quarters. You w an t to choose 15 coins th at
are w orth exactly $4.35.
a. Write an d solve a system of eq u atio n s th at m odels th e situation.
b. Is your solution reasonable in term s of th e original problem? Explain.Solve each system. Explain why you chose the method you used.- 4 x + 5 j/ = 3 15. 2x + 7 y = - 2 0 16. 5x+2y=17
3x-2y=8 y = 3x+7 x-2y = 8
@ 17. Reasoning Find A and B so th a t th e system below h as th e solution (2, 3).
A x — 2 By = 6
3 Ax - By = - 1 2
@ 18. Think About a Plan A tugboat can pull a b o at 24 m i dow nstream in 2 h. Going
upstream , th e tugboat can pull th e sam e b o at 16 m i in 2 h. W hat is th e speed of the
tugboat in still w ater? W hat is th e speed of th e current?- How can you use th e form ula d = rt to h elp you solve the problem?
- How are th e tugboat's speeds w h en traveling u p strea m an d dow nstream related
to its speed in still w ater a n d th e speed of th e current?
Open-Ended Without solving, decide which method you would use to solve
each system: graphing, substitution, or elimination. Explain.- y=3x-l 20. 3m-4n = l 21. 4s-3f=8
y = 4x 3m — 2 n = —l t = —2s—l - Business A perfum e m aker h as stocks of two p erfum es on h an d. Perfum e A sells
for $15 p e r ounce. Perfum e B sells for $35 p er ounce. How m u ch of each should be
com bined to m ake a 3-oz bottle of perfum e th a t can b e sold for $63?
(222^ 23. Chem istry In a chem istry lab, you have two vinegars. O ne is 5% acetic acid, an d
one is 6.5% acetic acid. You w an t to m ake 200 mL of a vinegar w ith 6% acetic acid.
How m any milliliters of each vinegar do you n e e d to mix together?
^A pply 13.
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