Question 1102858
without calculating, solve for z and explain why

3x + 2y + 4z -7w = 4

2x -5y +7z + 2w  = 7

4x +2y -3z -3w =  -3

x -11y +2z +9w = 2
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The coefficient of z equals the right side.
--> z = 1
x = y = w = 0