Answer:
26.14
Step-by-step explanation: Just subtract.
Answer:
-499,485.
Step-by-step explanation:
We can transform this to an arithmetic series by working it out in pairs:
6^2 - 7^2 = (6-7)(6+7) = -13
8^2 - 9^2 = (8-9)*8+9) = -17
10^2 - 11^2 = -1 * 21 = -21 and so on
The common difference is -4.
The number of terms in this series is (998 - 6) / 2 + 1
= 992/2 + 1 = 497.
Sum of n terms of an A.S:
= n/2 [2a1 + (n - 1)d
Here a1 = -13, n = 497, d = -4:
Sum = (497/2)[-26 - 4(497-1)]
= 497/2 * -2010
= -499,485.
Answer:
13) 25 and 17
14) cupcakes = $5
brownies = $3
Step-by-step explanation:
13) you can set this up as equations
so x + y = 42
x-y = 8
solve simultaneously by subtracting from each other
2y = 34
y= 17
if y = 17
42 - 17 = 25 = x
14) set up as equations again
Ben 7c + 10b = 65
franklin 7c +7b = 56
subtract from eachother
3b = 9
b = $3
7c + 10(3) = 65
7c = 35
c = $5
I think that would be 100 million pounds of coal.
Answer:22
Step-by-step explanation:
