The row instruction is written next to Row 1, meaning that we are to replace Row 1 according to the instruction, 3 R₁ 2 R₂. In words, this means

"Replace Row 1 (the top row) by 3 times the top minus 2 times the bottom."

Now, rewrite the top row, going from left to right, as follows:

First entry:

3(top) 2(bottom) = 3(1) 2(3) = 3 6 = 3.

Therefore, the first entry is 3.

Second entry:

3(top) 2(bottom) = 3(2) 2(0) = 6 0 = 6.

This is the second entry.

Third entry:

3(top) 2(bottom) = 3(5) 2(9) = 15 18 = 3.

Thus, the new first row is

[3 6 3].