What does linear combination of strings mean?

Question

Linear algebra

From this photo, a linear combination of rows, is it just a linear combination of a row-vector by a factor of 1?

Well, or just for example, if the matrix is ​​​​3x3, then some kind of row, for example, a1: a1 is equal to the sum of others multiplied by a factor of 1, because a1 = a2 * 1 + a3 * 1, Is this a linear combination of strings?

Answer 1

Yes, the coefficient only has to be different from zero.