Write the equations:
1a. One week a computer store sold a total of 36 computers and external hard drives. The revenue from these sales was $27,710. If computers sold for $1180 per unit and hard drives for $125 per unit, how many of each did the store sell?
x+y=36
1180x+125y=27,710
100
Solve the equations:
x+y=36
1180x+125y=27,710
x (computers) = 32
y (hard drives) = 14
100
1a. 5x+11 < 26
x<3
(-infinity,3)
100
1c. 7(x+4) -13 < 12 +13(3+x)
x > -6
(-6, infinity)
200
Write the equations:
1b.You invested $7000 in two accounts paying 6% and 8% annual interest. If the total interest earned for the year was $520, how much was invested at each rate?
x+y=7000
.06x+.08y=520
200
Solve the system of equations:
x+y=7000
.06x+.08y=520
$2000 at 6%
$5000 at 8%
200
1b. -9x > 36
=
(greater than or equal to)
x<4 (x is less than or equal to 4)
=
(-infinity, 4]
200
2a. 8(x+1) < 7(x+5)+x
=
(less than or equal to)
all reals
(-infinity, infinity)
300
Write the cost function and revenue function:
2. A company that manufactures small canoes has a fixed cost of $18,000. Additionally, it costs $20 to produce each canoe. The selling price is $80 per canoe.
C(x)=18,000+20x
R(x)=80x
300
Find the break-even point:
C(x)=18,000+20x
R(x)=80x