How Many Terms Of The Arithmetic Sequence 20,18,16, Must Be Added So That The Sum Will Be -100? With Solution Pls. Thanks<3
how many terms of the arithmetic sequence 20,18,16, must be added so that the sum will be -100? with solution pls. Thanks<3
Answer:
n= 71
Step-by-step explanation:
Hello there! Here is the answer for your problem:
Given:
A₁= 20
d= -2 18-20
Sn= -100
n= ?
Needed Equation:
Sn= 2A₁ + (n- 1) d
-100 = 2 (20) + (n- 1) (-2) Substitute
-100 = 40- 2n + 2 Simplify
2n = 100+ 40 + 2 Add like terms
2n= 142 Simplify
n= 71 Final Answer
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