First find the total of 2n by using the formula for summation:
( n(n+1))/2
Replace n with 24 and multiply the equation by 2 to get 2n:
2(24(24+1)2) = 2(24*25/2) = 2(600/2) = 600
Now find the total for -3 using the summation for a constant, which is multiplying n by the constant:
-3 x 24 = -72
Now add both summations together:
600 + -72 = 600 - 72 = 528.
The answer is 528.
She should save $38,450.39.
The formula for the amount of money in an interest-bearing account that is compounded is

where A is the total amount in the account, p is the amount of principal invested, r is the interest rate as a decimal number, n is the number of times per year interest is compounded, and t is the number of years. Using our information we have:

Divide both sides:
Trigonometry and Pythagoras I think
Number 1 is C.
Number 2 is C.
Did you need all of them?