# algebra

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9. 9/5w + 8/w
** Cannot be simplified. Am I correct??

14. The number of instrctions N performed per second by a computer varies directly as the speed S of the computer's internal processor. A processor with a speed of 20 megahertz an perform 1,800,000 instructions per second.

a. Find an equation of variation
N =

b. The same processor perform _____ instructions if it is running at a speed of 180 megahertz.

18. To travel a fixed distance, the numver of gallons needed is inversely proportional to the miles-per-gallons rating P of the car gets 42 miles-per-gallon (mpg) needs 33 gal to travel the distance.

a. An equation of variation is N=
b. A car that gets 77 mpg needs ____ gallons of gas.

• algebra - ,

#9.
If you mean
9/(5w) + 8/w then that is
9/(5w) + 40/(5w) = 49/(5w)

If you mean
(9/5) w + 8/w then that is
9w^2/(5w) + 40/(5w) = (9w^2+40)/(5w)

#14.
N = kS
1.8 = k*20 (in M)
k = .09, so
N(S) = .09S
N(180) = .09*180 = 16.2

#18.
N = k/P
33 = k/42
k = 1386, so
N(P) = 1386/P
N(77) = 1386/77 = ?