Question 447729
Notice that {{{36}}} is a perfect square, and {{{m^2}}} is a
perfect square, so you can write them like this:
{{{ 6^2*m^2 = (6m)^2 }}}
Also, {{{81}}} is a perfect square {{{ 81 = 9^2}}}
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A general rule of algebra is:
{{{ a^2 - b^2 = (a+b)*(a-b) }}}
In your case, you have:
{{{ (6m)^2 - 9^2 = (6m + 9)*(6m - 9) }}}
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The above rule is worth remembering. Hope this helps