3x3 Matrix Problem - Gaussian Elimination

Hello, this is the begining to my Pre-Calc class and I'm having issues with a 3x3 Matrix.

The problem is as follows:

8r-s+t=34

2r+2s-3t=25

r-3s+2t=-10

This is what I have so far:

[8 -1 1 | 34]

[2 2 -3 | 25]

[1 -3 2 |-10]

R1<->R3

[1 -3 2 | -10]

[2 2 -3 | 25]

[8 -1 1 | 34]

-2R1+R2

[1 -3 2 |-10]

[0 -4 6 |-50]

[8 -1 1 | 34]

-8R1+R3

[1 -3 2| -10]

[0 -4 6| -50]

[0 23 -8|-272]

I'm stuck here. I know that I need to get R2C2 to a 1 and assuming I'm correct its a problem of simple math, but other than use a calculator to figure it out by trial and error how do I find out a simple method to get the one? I realize this is a simple case of math, but to be frank I'm in an online class and I don't get the great base of Math most get.

Thanks for any advice anyone can give.