The operation we are using to replace Row 2 is R₂-3 R₁, that is,

Bottom minus 3 times Top.

Working from left to right, we get

(Bottom)-3(Top)
3 - 3(1) = 0
5 - 3(-5) 5 + 15 = 20
5 - 3(2) = -1

Therefore, the new bottom row is

[0   20   -1]

and the matrix becomes

	1	-5	2
	0	20	-1

---

Close this window to return to the tutorial.