Answer :

To express the sum

[tex]\[ 1 + 2 + 3 + \cdots + 49 \][/tex]

using summation notation, follow these steps:

1. Identify the starting and ending points of the summation. The series begins at 1 and ends at 49.
2. Recognize the general form of the series terms, which in this case is simply [tex]\(k\)[/tex], where [tex]\(k\)[/tex] starts from the first term and ends at the last term of the series.

Using this information, the summation notation can be written as:

[tex]\[ \sum_{k=1}^{49} k \][/tex]

So, the sum

[tex]\[ 1 + 2 + 3 + \cdots + 49 \][/tex]

can be expressed using summation notation as:

[tex]\[ \sum_{k=1}^{49} k \][/tex]