Question 1146879
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<pre>
Selma = 12 + {{{t/5}}}  boxes, where "t" is the time in minutes.


Trudy = 18 + {{{t/7}}}  boxes.


Your equation is


    Selma = Trudy,


or, equivalently,


    12 + {{{t/5}}} = 18 + {{{t/7}}}.


Your task is to find "t" from this equation.


First step is to write it in this form


    {{{t/5}}} - {{{t/7}}} = 18 - 12 = 6.


Next step is to multiply both sides by 35.
</pre>


Having these instructions, you should be able to complete the solution on your own.