Question 985676
<pre>
           (x+7)² = x² + mx + 49

       (x+7)(x+7) = x² + mx + 49
x² + 7x + 7x + 49 = x² + mx + 49
    x² + 14x + 49 = x² + mx + 49

Subtract x² and 49 from both sides

    x² + 14x + 49 = x² + mx + 49
   -x²        -49  -x²       -49
   -----------------------------
         14x      =      mx

Divide both sides by x

               14 = m

Edwin</pre>