Answer:
The answer is 2178, if you multiply it by 4, you would get 8717
Step-by-step explanation:
HERE ARE THE STEPS IF YOU NEED THEM!!
1. Lets say the number is written as ABCD (1000a+100b+10c+d).
2.Multiplying it by 4, gives you DCBA (1000d+100c+10b+a)
3. By divisibility of 4, BA is a two-digit number divisible by 4.
4.Now, the largest possible value of ABCD is 2499, because anything more will result in a five digit number when multiplied by 4.
5. Out of the two possibilites 1 and 2 for A, [3] follows that A is even, so 2.
6. From [5], D is either 8 or 9. However, since D times 4 would end in 2, D is 8.
7. Using [2], 4000a+400b+40c+4d = 1000d+100c+10b+a, which would simplify to 2c-13b = 1 after substituting A = 2 and D = 8.
8.The only possible value of (b,c) where they would both be single digit integers is (1,7). Also to note from [3], B is odd. And from [4], B is either 1 or 3.
