which one is the correct answer

Answer:
B.
Step-by-step explanation:
Other equations don't have any value of x.
Answer:
Because if you see.. The component of x will get canceled in each of the other 3 options.. ( 2x - 2x) which means no solution.. In option B.. 2x + 2x will give 4x..= 31-31 = 0..
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