Question

\[\sum_{51}^{77} 2i-1\]

Answer 1

whats the process of getting the answer though?

Answer 2

\[ 2\sum_{55}^{77}i - (77-51) \]
^ this is an Arithmetic sequence with first term 55 and common difference 1

Answer 3

so all i do now is subtract 77-51?

Answer 4

\[ 2 \times 55(77-51)(77-51+1)/2 - (77-55)\]

Answer 5

that was how i was solving it and my answer was 3328 but it was wrong?