<PRE><B>Question 120535</B>
Call the sides of the original square {{{x}}}
The area of the original square is {{{x^2}}}
When I decrease the sides by 3 cm, I have an area
of {{{(x - 3)(x - 3)}}}
In words:
81 cm^2 = (original area) - (area reduced by 3cm on each side)
{{{81 = x^2 - (x - 3)^2}}}
{{{81 = x^2 - (x^2 - 6x + 9)}}}
{{{6x - 9 = 81}}}
{{{6x = 90}}}
{{{x = 15}}}
The original square is 15 cm x 15 cm
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