Question

What two numbers, if added together, would equal -15 but when multiplied together would equal -42

Answer 1

Consider factors of 42, then if the factors can be added or subtracted.

42 = 42 * 1
42 = 21 * 2
42 = 14 * 3
42 = 7 * 6

Since none of these can be added or subtracted to equal 15, no intergers satisfy these criteria.