evaluate the sum \$\\sum_{i=4}^{9} i\$

$evaluate the sum \$\\sum_{i=4}^{9} i\$$

evaluate the sum \$\sum_{i=4}^{9} i\$

The summation $\sum_{i = 4}^{9} i$ means we add the integers from 4 to 9. So we write out the terms: $4 + 5 + 6 + 7 + 8 + 9$.

First, add 4 and 5: $4 + 5 = 9$. Then add 6: $9 + 6 = 15$. Next, add 7: $15 + 7 = 22$. Then add 8: $22 + 8 = 30$. Finally, add 9: $30 + 9 = 39$.

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