class Hash
def remove_hash(other_hash)
delete_if { |k,v| other_hash[k] == v }
end
end
squares = { 1 => 1, 2 => 4, 3 => 9 }
doubles = { 1 => 2, 2 => 4, 3 => 6 }
squares.remove_hash(doubles)
squares # => {1=>1, 3=>9}