Answer:
b
Step-by-step explanation:
40 + 90 =130
180-130=50
Let S be the sum,
S = 2 + 4 + 6 + ... + 2 (n - 2) + 2 (n - 1) + 2n
Reverse the order of terms:
S = 2n + 2 (n - 1) + 2 (n - 2) + ... + 6 + 4 + 2
Add up terms in the same positions, so that twice the sum is
2S = (2n + 2) + (2n + 2) + (2n + 2) + ... + (2n + 2)
or
2S = n (2n + 2)
Divide both sides by 2 to solve for S :
S = n (n + 1)
The answer is $31 dollars because there is 31 days in August
Answer:
<h2>100</h2>
Step-by-step explanation:
BIDMAS
do the bracket first
50+20=70
70+30=100
