
Christopher R. answered 12/05/16
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Let x=the number of swimmers finished first place.
y=the number of swimmers finished second place.
z= the number of swimmers finished third place.
The first equation represents the total number of individuals who participated in the high school swim meet in which is:
x+y+z=24
The second equation represents the combined total score in which is:
3x+2y+z=53
Since the problem states that there were as many first place finisher as there were second place and third place finishers combined indicates x=y+z. This last equation is to be substituted into the first two equations; thereby, reducing them into two equations with two unknowns. Hence, the two equations are:
(y+z)+y+z=2y+2z=24
3(y+z)+2y+z=3y+3z+2y+z=5y+4z=53
Thus,
2y+2z=24
5y+4z=53
Next, multiply the first equation by -2 in which the system becomes:
-4y-4z=-48
5y+4z=53
Add the two equations to eliminate the variable 'z' to reduce the two equations to one equation.
y=5
2*5+2z=24
10+2z=24
-10 -10
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2z=14 Divide both sides by 2 in which makes:
z=7
Finally, x=y+z=5+7=12
Therefore, the following number of swimmers who finished first, second, and third: 1st) 12, 2nd) 5, and 3rd) 7.

Christopher R.
12/05/16