<PRE><B>Question 1186290</B>
&lt;br&gt;
The solution from the other tutor leaves out one of the constraints and so suggests invalid answers....&lt;br&gt;
x hamburgers at $6 each, plus y tacos at $2, must cost at most $30&lt;br&gt;
6x+2y&lt;=30
3x+y&lt;=15
y&lt;=-3x+15&lt;br&gt;
The total number of hamburgers and tacos must be at least 8&lt;br&gt;
x+y&gt;=8
y&gt;=-x+8&lt;br&gt;
A graph; solution must have x and y non-negative, and must be on or below the red line and on or above the green line&lt;br&gt;
{{{graph(400,400,-2,10,-2,20,-3x+15,-x+8)}}}&lt;br&gt;
You can find one or more solutions -- using the graph if you want.&lt;br&gt;
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