Question 380376
2. x=y-1
y=4-2x 
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Sub for x in the 2nd eqn
y = 4 - 2(*y-1)
y = 4 - 2y + 2
y = 6 - 2y
3y = 6
y = 2
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x = y-1
x = 1
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Do the others the same way.