Answer:
+10 and - 9
Step-by-step explanation:
If we consider the multiples of - 90
± 1, ± 2, ± 3, ± 5, ± 6, ± 9, ± 10, ± 15, ± 30, ± 90
The combination of multiples which multiply to - 90 and add to + 1 are
+ 10 and - 9
since 10 × - 9 = - 90 and 10 - 9 = 1
