"."
"; //+++++++++++++++++++++ echo $z1 = rand(4 , 9); echo " + "; echo $z2 = rand(4 , 9); echo " + "; echo substr($op , 1 , 1); echo " = ".$op2 = $z1 + $z2 + substr($op , 1 , 1); echo "
"."
"; //---------------------- echo $n1 = rand(0 , 9); echo "
"; echo $op3 = $op2 - $n1; echo "
"."
"; $fn = $z1.$n1.$x1.$z2.$x2.$op.$op2.$op3; if (strlen($fn) == 11) { echo $z1.$n1.$x1.$z2.$x2.$op.$op2.$op3; } else {echo "N != 11";} ?>