what number is obtained by adding the units digits of 734 ^ 98 and 347 ^ 81 ?
"the units digit of 734 ^ 98 is 6 because 4 raised to the power of an even integer ends in 6 . the units digit of 347 ^ 81 is 7 because powers of 7 end in 7 , 9 , 3 or 1 cyclically . since 81 is in the form 4 n + 1 , the units digit is 7 . then 6 + 7 = 13 . the answer is d ."
subtract(subtract(98, 81), divide(98, add(const_1, const_10)))