How do you find the 25th partial sum of the arithmetic sequence #a_1=100, a_25=220#?

Related questions

• How do I find the sum of an arithmetic sequence?
• What is the formula for the sum of an arithmetic sequence?
• What are common mistakes students make when finding the sum of an arithmetic sequence?
• How do I find the sum of an arithmetic sequence on a calculator?
• How do I find the partial sum of an arithmetic sequence?
• How do I find the partial sum of an arithmetic sequence on a TI-84?
• What is meant by the sum of an arithmetic sequence?
• How do I find the sum of the arithmetic sequence 3, 5, 7, 9, ..., 21?
• What is the sum of the arithmetic sequence 22, 13, 4?
• How do you find the sum of the first 25 terms of the sequence: 7,19,31,43...?