<PRE><B>Question 961155</B>
your calculations are correct except for the last value for y
y = 1.5x +607.5 
should be
y = -1.5x +607.5
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now graph the two equations
y = 520 -x 
y = -1.5x +607.5
first equation will be red color and second equation is green color
{{{ graph( 300, 200, -650, 650, -650, 650, -x +520, -1.5x +607.5) }}}
from the graph, our point of intersection is (175, 345)
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to check the work set your two equations for y equal to each other
520 -x = -1.5x +607.5
add x to both sides of =
520 = -.5x +607.5
subtract 607.5 from both sides of =
-87.5 = -.5x
divide both sides of = by -.5
-87.5/-.5 = x
175 = x
now substitute for x in the equation
y = 520 -x
y = 520 - 175 = 345
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there are 175 adults and 345 students

  
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