Question 563859
{{{ 90 - 2x = 2*( 52 - 2x ) }}}
{{{ 90 - 2x = 104 - 4x }}} 
{{{ 4x - 2x = 104 - 90 }}}
{{{ 2x = 14 }}}
{{{ x = 7 }}}
The squares should be 7 cm x 7 cm
check:
{{{ 90 - 2x = 2*( 52 - 2x ) }}}
{{{ 90 - 2*7 = 2*( 52 - 2*7 ) }}}
{{{ 90 - 14 = 2*( 52 - 14 ) }}}
{{{ 76 = 2*( 38 ) }}}
OK