- Boating A b o at is traveling in a river w ith a c u rren t th a t has a speed of 1.5 k m / h. In
one hour, th e b o at can travel twice th e distance dow nstream th a t it can travel
upstream. W hat is the b o a t’s speed in still water? - Reasoning A stu d en t claim s th a t th e b est way to solve th e system at the right is by
substitution. Do you agree? Explain. - Entertainm ent A co n testan t on a quiz show gets 150 points for every correct
answ er an d loses 250 points for each incorrect answer. After answ ering 20 questions,
the contestant has 200 points. How m any q uestions has th e co n testan t answ ered
correctly? Incorrecdy?
C h a lle n g e 2 7. N u m b e r T h e o ry You can rep resen t th e value of any two-digit n u m b e r with the
expression 10a + b, where a is th e te n s’ place digit a n d b is the o n es’ place digit. For
example, if a is 5 a n d b is 7, th e n th e value of th e n u m b e r is 10(5) + 7, or 57. W hat
two-digit n u m b e r is d escribed below?
- I h e o n es’ place digit is one m ore th a n twice the tens' place digit.
- I h e value of th e n u m b e r is two m ore th a n five tim es th e o n es’ place digit.
- Mixed Nuts You w ant to sell 1-lb jars of m ixed p ea n u ts an d cashew s for $5. You
pay $3 p e r p o u n d for p ea n u ts an d $6 p er p o u n d for cashews. You plan to com bine
4 p arts p ea n u ts an d 1 p a rt cashew s to m ake your mix. You have sp en t $70 on
m aterials to get started. How m any jars m u st you sell to b reak even?
St a n d a r d i ze d Test Pr ep
^SAT/ACT 29. Last year, one fourth of the stu d en ts in your class played an instrum ent. Ih is year,
6 students jo in ed th e class. Four of the new stu d en ts play an instrum ent. Now, one
third of the stu d en ts play a n instrum ent. How m any students are in your class now?
CD 18 GD 24 CO 30 (0 48- W hich answ er choice shows 2x — y = z correctly solved for y?
CDy = 2x + z COy = 2x - z CO y = -2x + z CDy=-
Short 31. W hat is an equ atio n of a line passing th rough th e points (3,1) an d (4, 3) w ritten in
^Response slope-intercept form?Mixed Review
Solve each system using elimination.- x + 3y= 11 33. 2x + 4 y = - 1 2 34. 5 x + 8 y = 40
2x + 3 y = 4 —6 x + 5 y = 2 3 x - 1 0 y = -
Get Read y! To p r e p a r e f o r Le sso n 6 - 5 , d o Ex e r c i se s 3 5 - 3 7.
Solve each inequality. Check your solution.- 3a + 5 > 20 36. 2d - 3 > Ad + 2 37. 3 {q + 4) < - 2
y - 3x = 4
y - 6 x = 12-2x — z1See Lesson 6-3.13\q - 8See Lesson 3-4.3 9 2 Chapter 6 Sy st e m s o f Eq u a t i o n s a n d I n e q u a l i t i e s