The answer for 7+3 will be 410, because the first one is (5-3=2) (5+3=8), =28, and to get the answer you have to subtract the first number with the second number, and then add the the first number with the second one again. If 9-1= 8, and 9+1= 10, the answer of the second one will be 810. 7-3=4, 7+3=10, so the answer will be 410.