MATH
posted by Christine .
In the equation
4*ABCDE= EDCBA
each letter represents a different nonzero digit. Determines the sum
A+B+C+D+E
i don't know how to do this

start with E. 4e is 20 + A or 10+A or A.
but it has to be divisible by 4, so A is 4 or 2 or 6. Think that out.
if A is 4, then 4E is 24, or 4, which means E is 6, or 1
Now try those combinations for A and E, and work on the other letters. Because I am so helpful, look at the leading digits: IF A is 4, then can E be 6? Look at the first digit now 4A=E+10 or 20. But the number EDCBA is the same number of digits as ABCDE, so no carry is involved, so E cannot be 6. So E is 1, which means A is 4
Now work on the tens digit the same way. Have fun. 
The product of fivedigits number by four equal fivedigit number>A=1 or A=2.
The last digit of number 4E is A>A=2,E=8
4*21978=87912 
Hmmm. I agree.