Answers

2016-08-04T07:07:30+08:00
Area rec=420;

420=lw;

l=3w-1;

420=3w-1]w;
420=3w^2-w;
3w^2-w-420=0;

w=1+71]/6;
w=72/6;

w=12 cm;

l=3(12)-1;
=35 cm
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