29.Sharon Klein has candy that sells for $1.30 per lb, to be mixed with candy selling for
$0.90 per lb to get 100 lb of a mix that will sell for $1 per lb. How much of each type
should she use?290 CHAPTER 4 Systems of Linear Equations and Inequalities
Number of Percent (as Amount of
Liters a decimal) Pure Antifreeze
x 0.40
y 0.70
90 0.50Amount of
Principal Rate Interest
x 0.03
y 0.04
$18,00030.A 40% antifreeze solution is to be mixed
with a 70% solution to get 90 L of a 50%
solution. How many liters of the 40%
and 70% solutions will be needed?31.Nancy Johnson invested $18,000. Part
of it was invested at 3% annual simple
interest, and the rest was invested at 4%.
Her interest income for the first year
was $650. How much did she invest at
each rate?32.A certain plane flying with the wind travels 540 mi in 2 hr. Later, flying against the same
wind, the plane travels 690 mi in 3 hr. Find the speed of the plane in still air and the speed
of the wind.4.5 Graph the solution set of each system of linear inequalities.
33. 34. 35. 36.
y... 2xÚ- 13 x-y... 3
2 x 7 yx+y 63
2 x+ 3 y... 6yÚ 2 x
x-y... 4x+yÚ 2MIXED REVIEW EXERCISES
Mortgage Shopping4 8 12 16
0600650700YearMonthly Payment(in dollars)FixedVariableA. B. C. D.
yÚ 1xÚ 3
y... 1xÚ 3
yÚ 1x... 3
y... 1x... 3xy1
0 3Solve each problem.
37.Patricia Pinkston compared the monthly
payments she would incur for two types of
mortgages: fixed rate and variable rate.
Her observations led to the graph shown.
(a)For which years would the monthly
payment be more for the fixed rate
mortgage than for the variable rate
mortgage?
(b)In what year would the payments be
the same, and what would those pay-
ments be?
38.Concept Check Why would it be easier to solve System B by the substitution method
than System A?
System A: System B:39.Concept Check Which system of linear inequalities is graphed
in the figure?2 x+ 5 y=- 5 y= 3 x- 2- 5 x+ 6 y=- 7 2 x+ 9 y= 13
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