Numbers in a problem or related numbers that are easy to work with mentally
-4 and -5
because to get 16 to 12 you have to subtract 4 but it wants you to add so you put a negative sign infront of it.
and a negative multiply by a negative equals a positive so -3×-5=15
Answer:
7
Step-by-step explanation:
20 - 12 = 8
15 - b = 8
-b = 8 - 15
b = 7 ( -ve signs will become +ve)