Answer:
Step-by-step explanation:
subtract 9 from both sides
x=3
Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
<h3>
Answers:</h3><h3>
6 quarters</h3><h3>
2 dimes</h3>
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Work Shown:
d = number of dimes
q = number of quarters
q = d+4 since she has 4 more quarters than dimes
$1.70 = 170 cents
10d = value of all the dimes in cents
25q = value of all the quarters in cents
10d+25q = total value of all the coins in cents
10d+25q = 170
10d+25( q ) = 170
10d+25( d+4 ) = 170 .... plug in q = d+4
10d+25d+100 = 170 .... distribute
35d+100 = 170
35d = 170-100 ..... subtract 100 from both sides
35d = 70
d = 70/35 ... divide both sides by 35
d = 2
He has 2 dimes
q = d+4
q = 2+4
q = 6
He also has 6 quarters
------------------
Check:
1 dime = 10 cents
2 dimes = 20 cents ..... multiply both sides by 2
1 quarter = 25 cents
6 quarters = 150 cents ..... multiply both sides by 6
(2 dimes) + (6 quarters) = (20 cents) + (150 cents) = 170 cents
This confirms the answers.
Answer:
(a) The dependant veriable is the $120 per hour and the independant veriable is the $75 consultaion fee.
(b) The table of vaules for this would look like this, 
, where C = cost and T = time.
(c) The relationship between C and T is linear, beacause with the more hours you take the cost increases.
(d) Yes, it is sensible because the points would be in line due to the steady increase of the hourly rate.
(e) For every hour spent the cost increases 120 dollars.
(f) The fixed cost is 75 dollars for consultation and the veriable cost is 120 per hour.
Answer:
48 cents
Step-by-step explanation:
