Question 267285
w + 8s = - 42 multiply by 9 & add.
-9w - s = -48 
9w+72s=-378
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71s=-426
s=-426/71
s=-6 ans.
w+8*-6=-42
w-48=-42
w=-42+48
w=6 ans.
Proof:
-9*6-(-6)=-48
-54+6=-48
-48=-48