We know the perimeter is the total sum of all sides of the shape, we can use this to form an equation: the perimeter=1st side + 2nd side + 3rd side + 4th side 39a-7=9a+(5a+1)+(17a-6)+4th side.
Collect like terms to get 39a-7=31a-5+4th side
If we move everything but the 4th side over to the left we can solve
C. 8a-2=4th side is the correct answer
-1 is greater then 1.05 then 1.05 then 1.55
so the answer is C
-13 hope this answers tour question
This is not a full question. If you were given the amount at the begining of 1970 (we'll call it x) and the amount at the end of 1980 (we'll call it y), we should solve them accordingly:
y-x=? (calling the answer a)
a/y=%(not answer yet, call this b)
b+100=answer
