Spent over 2 hours on this question please help. three systems of linear equations question. Solved part 1 part 2 has given me trouble. :l Please help!

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anonymous · Answer

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anonymous · Answer

I had to solve for the -2 and need to solve for the box of the second set of answers
I think it's D but I don't know what number and or fraction I need to solve it.

anonymous · Answer

The system generally counts it wrong if I put in a one or a zero.

anonymous · Answer

I cant find anything to solve for B

anonymous · Answer

omg thank you thank you thank you you're a life saver.