Download WS ANSWERS – Two-Variable Systems Applications

WS ANSWERS – Two-Variable Systems Applications
1. X=# $20 bills
y = # $50 bills
x+y=15
20x + 50y = 390
12 twenties, 3 fifties
2. s=#single tickets
c=# couples tickets
s + 2c = 128
20s + 35c = 2280
16 single, 56 couples
3. v= vertex < msr
b=base < msr
v = 2b – 40
2b + v = 180
55 deg. for base,
70 deg. for vertex angle
4. b=base
L= leg
b + 2L = 23
b + 2(2L) = 41
5, 9, 9 and 5, 18, 18
5. j= # pairs of jeans
s= # shirts
25j + 18s = 441
20j + 20s = 420
9 jeans, 12 shirts
6. x= # 20 ton bins
y = # 15 ton bins
x + y = 30
20x + 15y = 510
12 20-ton, 18 15-ton
7. r = rate of speed of helicopter
w = wind speed
(5/3)(r + w) = 300
2(r – w) = 300
165 mph = r
16 mph = wind
8. r = rate of speed of plane
W = wind speed
4(r – w) = 1000
(10/3)(r + w) = 1000
plane 275 mph,
wind 25 mph
9. f = cost of first minute
A= cost of additional minutes
f + 6a = 10
f + 3a = 6.40
1st min. $2.80,
add. min. $1.20 each
10. f = fixed cost
g = cost per guest
f + 25g = 300
f + 40g = 420
$100 fixed cost,
$8 per guest
11. x= investment in stocks
Y = investment in bonds
.15x + .06y = 930
x + y = 8000
$5000 at 15%,
$3000 at 6%
12. a= # hrs worked by apprentice
p= #hrs worked by plumber
p= a + 3
28p + 15a = 213
a= 3, p = 6
apprentice $45,
plumber $168
13. r = rate of speed of the plane
d = distance
(7/3)(r – 15) = d
(7/5)(r + 15) = d
distance is 105 km
plane’s speed = 60 km/h
15. f = fixed weekly charge
m = cost per mile
f + 520m = 250
2f + 800m = 440
$.25 per mile,
$120 per week