Answer:
780
Step-by-step explanation:
So when you're adding consecutive numbers like this. 1+2+3...+39. You add 39 and 1. This is 40. 2+38 is 40. This is a pattern. Now, we do 40 multiplied by 39 and this will give you the number 1620. After this you would have to divide this product by 2. The answer will soon be 780.
Step-by-step explanation:
Choice a is a good one by the way
Answer:
Step-by-step explanation:
me too..
All you do is use the a+b=c formula lets plug it in
15+b=35
15+20=35
35=35
The answer is 20
