2. Additional Example 3: Money Application
Edgarโs August profit of $137 was at least $20
higher than his July profit. What was Julyโs
profit?
Let p represent the profit increase from July to
August.
August profit was at least $20 higher than Julyโs profit.
$137
โฅ
20
+
p
137 โฅ 20 + p
Subtract 20 from both sides.
-20 -20
117 โฅ p
p โค 117
Rewrite the inequality.
Julyโs profit was at most $117.
3. Check It Out: Example 3
Rylanโs March profit of $172 was at least $12
less than his February profit. What was
Februaryโs profit?
Let p represent the profit decrease from February to
march.
March profit was at least $12 less than Februaryโs profit.
$172
โฅ
-12
+
p
172 โฅ -12 + p
Add 12 to both sides.
+12 +12
184 โฅ p
p โค 184
Rewrite the inequality.
Februaryโs profit was at most $184.
4. Fridayโs high temperature was 20 ยฐF. Saturdayโs
high temperature was forecast to be no more
than 8 ยฐF warmer than Fridayโs high
temperature. According to the forecast,
what are the possible high temperatures for
Saturday?
X < 28
5. In order for a field trip to be scheduled, at
least 30 students must sign up. So far, 23
students have signed up. At least how many
more students must sign up in order for the
field trip to be scheduled?
X + 23 > 30
-23 -23
x > 7
6. Additional Example 3: Application
It cost Josh $85 to make candles for the craft
fair. How many candles must he sell at $4.00
each to make a profit?
Since profit is the amount earned minus the
amount spent, Josh needs to earn more than $85.
Let c represent the number of candles that must be
sold.
4c > 85
Write an inequality.
4c > 85
Divide both sides by 4.
4
4
c > 21.25
Josh cannot sell 0.25 candle, so he needs to sell at
least 22 candles, or more than 21 candles, to earn a
profit.
7. Check It Out: Example 3
It cost the class $15 to make cookies for the
bake sale. How many cookies must they sell at
10ยข each to make a profit?
Since profit is the amount earned minus the
amount spent, the class needs to earn more than
$15.
Let c represent the number of cookies that must be
sold.
Write an inequality.
0.10c > 15
0.10c > 15
Divide both sides by .10.
0.10 0.10
c > 150
The class must sell more than 150 cookies to make
a profit.
8. 1. It cost $730 to put on the school play. How many
tickets must be sold at $6 a piece in order to make a
profit?
6t > 730 t > 121.7
so at least 122
1. It cost Sophia $530 to make wind chimes. How many
wind chimes must she sell at $12 apiece to make a
profit?
12x > 530
x > 44.17 so at least 45
9. 3. It cost the Wilson children $55 to make lemonade. How
many glasses must they sell at 75ยข each to make a
profit?
0.75x > 55
x > 73.3 so at least 74 cups
4. Jorgeโs soccer team is having its annual fund raiser. The
team hopes to earn at least three times as much as it
did last year. Last year the team earned $87. What is
the teamโs goal for
this year?
X > 87(3)
x > 261 so at least $261
