My suggestion is to look on google, there are plenty of answers and I think it will explain better than me.
Answer:
-24
Step-by-step explanation:

Write 130 words about two plants in separate room and only talk to one will it grow faster. It wants me to describe your results and state the conclusion you can draw from these resultsWrite 130 words about two plants in separate room and only talk to one will it grow faster. It wants me to describe your results and state the conclusion you can draw from these resultsWrite 130 words about two plants in separate room and only talk to one will it grow faster. It wants me to describe your results and state the conclusion you can draw from these resultsWrite 130 words about two plants in separate room and only talk to one will it grow faster. It wants me to describe your results and state the conclusion you can draw from these resultsWrite 130 words about two plants in separate room and only talk to one will it grow faster. It wants me to describe your results and state the conclusion you can draw from these results<span>Write 130 words about two plants in separate room and only talk to one will it grow faster. It wants me to describe your results and state the conclusion you can draw from these results
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I believe its -1 because x2-x1/y2-y1 good luck