Answer:
a) y = 9.95(x-3) + 20.00
b) Cost of 5 software packages = $39.90
Step-by-step explanation:
Given that:
Cost of 3 software at sale = $20
Cost of regular = $9.95
Let,
x be the number of software purchased.
We will subtract 3 from x because they cost $20.
y be the total cost.
y = 9.95(x-3)+ 20.00
Putting x=5 in expression
y = 9.95(5-3) + 20.00
y = 2(9.95) + 20.00
y = 19.90 + 20.00
y = $39.90
Hence,
a) y = 9.95(x-3) + 20.00
b) Cost of 5 software packages = $39.90
If you are factoring it you can factor it into (x+5)^2
<span>In statistics finding percentiles relates to the standard deviation and something called a z-score. For normally distributed data the z-score represents how many standard deviations above or below the mean that group is a part of. The z-score for normally distributed data for the 90th percentile is 1.28. The standard deviation is then multiplied by the z-score to find, in this case, the shotlrtest height needed to be in the 90th percentile of this population. In this case to be in the 90th percentile your height must be 60.27 inches.</span>
Let V, be the rate in still water and let C = rate river current
If the boat is going :
upstream, its rate is V-C and if going
downstream, its rate is V+C,
But V = 5C, then
Upstream Rate: 5C - C = 4 C
Downstream rate: 5C+C = 6C
Time = distance/Rate, (or time = distance/speed) , then:
Upstream time 12/4C and
Downstream time: 12/.6C
Upstream time +downstream time:= 2h30 ' then:
12/4C + 12/.6C = 2.5 hours
3/C + 2/C = 5/2 (2.5 h = 5/2)
Reduce to same denominator :
5C = 10 and Rate of the current = 2 mi/h
