The operation we are using to replace Row 1 is 4 R₁ + R₂, that is,

4 Times Top plus Bottom.

Working from left to right, we get

4(Top)+ (Bottom)
4(1) + 0 = 4
4(-5) + 20 = 0
4(2) + -1 = 7

Therefore, the new top row is

[4   0   7]

and the matrix becomes

	4	0	7
	0	20	-1

---

Close this window to return to the tutorial.