You have two unknown rates, so we need to develop two equations to solve for these unknowns (based on the information given on the problem statement):
5x + 10y = 725
x + y = 100
By substitution, we get:
5x + 10(100 - x) = 725
5x + 1000 - 10x = 725
-5x = 725 - 1000
-5x = -275
x = -275/-5 = 55
100 - 55 = 45
Thus:
The mechanic who worked for 5 hours charged his time at $55/hr, and the mechanic who worked for 10 hours charged his time at $45/hr.
To verify, plug and chug the results back into the original equations:
5(55) + 10(45) = 725
275 + 450 = 725
725 = 725 [OK]
55 + 45 = 100 [OK]
Here is the answer from SparkNotes
http://www.sparknotes.com/math/algebra2/operationsonfunctions/section3.rhtml
Answer:
x=14/5
Step-by-step explanation:
Group like terms
2x+8x+7=35
Add similar elements: 2x+8x=10x
10x+7=35
Subtract 7 from both sides:
10x+7−7=35−7
Simplify
10x=28
Divide both sides by 10
10x/10 =28/10
Simplify:
x=14/5
Answer:
It is a GP.
Step-by-step explanation:
a = 3
r = 2
a(n) term = ar^n
As it increases as multiples, it is a geometric progression or a GP.
