these numbers form an addition and subtraction fact family for 6,7,13 here the choices 7+13=20 13+7=20 13-13=0 13-0=13 and 7+0=7 6+0=6 13-0=13 13-13=0 and 7+6=13 6+7=13 13-6=7 13-7=6 7+6=13 13=7+6 13-6=7 7=13-6 which one is the right answer​