99 + 9 = 108
199
They are: 89+97 = 186
9797 is the largest two digit prime number.
It is: 79+83+89+97 = 348
679 is the product of the largest single-digit prime number and the largest two-digit prime number.
9 and 99
98 is the largest two digit number divisible by 7.
49
The units digit of a two digit number exceeds twice the tens digit by 1. Find the number if the sum of its digits is 10.
98 = 53 + (-3)3 = 125 + (-27)
269