Question 666395
Establish variables
x = wins
y = losses
...
x+y = 131
x = 15 + 3y
Substitute x into the first equation
...
15 + 3y + y = 131
Combine like terms
{{{cross(15) + highlight(3y) + highlight(y) - cross(15) = 131 - 15}}}
4y = 116
Divide both sides by 4
{{{cross(4)y/cross(4) = 116/4}}}
{{{highlight_green(y = 29)}}} losses
...
x = 15 + 3(29) = 15 + 87 = {{{highlight_green(102)}}} wins
...
Check  {{{cartoon(
29 + 102,
131)}}}
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