Answer:
127.5
Step-by-step explanation:
The given series is 26 + 24.5 + 23 + 21.5 + ... - 17.5
The first term of this series is a=26
The common difference is d=24.5-26=-1.5
The last term of the series is -17.5
The nth term is given by:
n=30
The sum of the series:
Step 2 is wrong and i don't know the other question
Answer:
Positive 8
Step-by-step explanation:
Since they're both negative numbers and it went from -9 to -1, you had to have added a positive number to get a lesser negative number. To put it simply, if you were to subtract 8 from 9, you'd get 1.
Twice means times 2.
1) 2(ab) gives twice the product of a and b.
2) (2a)b gives the product of twice a and b.
