Initial matrix

--------------------

Subtract 3 line twos from line 1

--------------------

Subtract 4 line twos from line 3

--------------------

Subtract 11/7 line ones from line 3

--------------------

Multiply line 3 by 7/72

--------------------

Substitute the value of w into lines 1 and 2

--------------------

Add 25 to line1 and subtract 7 from line2

--------------------

Multiply line one by 1/7

--------------------

Substitute the value of v into line 2

--------------------

Add 12 to line2

--------------------

Switch lines 1 and 2