Answer:
495
Step-by-step explanation:
In order to find the sum of the first 18 terms you have to find the 18th term and the first term using the equation given.
a1=3(1)-1 a1=2
a18=3(18)-1 a18= 53
Then plug in 53 for an, 18 for n, and 2 in for a1 in the sum equation: Sn=n/2(a1+an)
Sn=18/2(2+53) Solve for sn= 495
Answer:
Step-by-step explanation:
x= -1 and -3
What when multiplied is +3 but when added is 4? 3 and 1. You then get (x+3)(x+1) is the first part of the answer. If you want to find x, set x+3 to 0. x+3=0. Then subtract 3 from both sides to get x by itself. x= -3. Do the same with the x+1.
The answers is A
Explanation ;)