Question 669818
x+y = 990
8.5x + 4y = 6885
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Substitute for one variable, the idea is to isolate and solve for one variable at a time.
8.5(990-y) + 4y = 6885
8415 - 8.5y + 4y = 6885
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-4.5y = -1530
{{{highlight_green(y = 340)}}} students
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8.5x + 4(990-x) = 6885
8.5x + 3960 - 4x = 6885
4.5x = 2925
{{{highlight_green(x = 650)}}} non-students
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