Formula for perimeter a+b+a+b
12+5+12+5= 17+17= 34 .34=P
8/2(2+2)=X
8/2(4)=X
4(4)=X
16=X
Your answer would be X=16
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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