31 * 13 = 403.
Lining them up, you have 93 + 310 = 403.
a palindrome
13 + X = 31 Or 31 - 13 = X Ergo X = 18
(13) x (-31) = -403
~Long multiplication 31 X 13 310 93 = 403 ===== THe answer.
x+x+5 = 31 x+x = 31-5 2x = 26 x = 13
2 x 3 x 13 x 31 = 2418
13 x 31 = 403
1/365/195 = 13 x 5 / 39 x 513/39 = 13 x 1 / 13 x 31/3
2x + 5 = 31 2x = 31 - 5 = 26 x = 13
x-1/6 = 3/13 x works out as 31/78 Check: 31/78-1/6 = 3/13
Only 63 is a composite. 63 = 3 x 3 x 7 The other three numbers (13, 31, 61) are all prime numbers.
13 x 31
They are: X-XXXI-XIII respectively