Question 1030150
{{{ ( sqrt( 5x ) - 2*sqrt( y ) )*( sqrt( 5x ) + 2*sqrt( y ) ) }}} 
Is this correct? If so, this is in the form:
{{{ ( a + b )*( a - b ) = a^2 + ab - ab - b^2 }}}
{{{ ( a + b )*( a - b ) = a^2 - b^2 }}}
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In this case:
{{{ a = sqrt( 5x ) }}}
{{{ b = 2*sqrt( y ) }}}
So, the solution is:
{{{ a^2 - b^2 = ( sqrt( 5x ) )^2 - ( 2*sqrt( y ) )^2 }}}
{{{ a^2 - b^2 = 5x - 4y }}}