(m - n)(r - s) Hope this helps and heve a nice day!
Step-by-step explanation:

While subtracting , the sign of each term of second expression changes & remove the parentheses.
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Combine like terms. Like terms are those which have the same base. Only coefficients of like terms can be added or subtracted.
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In standard from , the expression should be written in such a way that the power of variables goes from highest to lowest.

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Answer:
1000
Step-by-step explanation:
1200*5/6=1000
Answer:
I think is is 5.4
Step-by-step explanation:
what I did is divided the problem