The two numbers that multiply to -30 and add up to 13 are 15 and -2. When you multiply 15 and -2, you get -30, and when you add them together, you get 13.
6.5 and 2
442
78
-11 and -13
6.5 and 2
104
338
13 is a prime number, so the only 2 whole numbers that multiply to 13 are 13 and 1.
442
78
-145
-11 and -13
13
-13
1 x 26, 2 x 13
1 and 52 2 and 26 4 and 13