To answer this, first think of all the numbers from 0 to 9 which, when multiplied by each other, result in 14.
There aren't that many; an easy way to find the right ones is to divide 14 by each of the numbers from 1 to 9.
Take those two numbers and put the smaller number in the tens place, the larger number in the ones place for the two digit number.
Then take that number and add 45.
The result should be the same two single digit numbers, but in reversed order.
For example, if the question read "Take two numbers whose product is 16 and add 54" you'd multiply through until you got 8x2 and 4x4. Then assume the first number is 28. Add 54, and the result is 82. This is the first two digits in reverse order. It wouldn't work if you'd tried 4x4 by the way, since reversing the digits is the same.