Answer :
ARITHMETIC MEAN is the average of the numbers.
You add it, and divide by 2.
a)
(475 + 615) /2 = 545
b)
(8 + - 12) /2
=(8-12)/2
-4/2
-2
c)
[tex]\frac{\frac{2}{3}+\frac{3}{4}}{2}=\frac{\frac{8+9}{12}}{2}=\frac{\frac{17}{12}}{2}=\frac{17}{12}\times\frac{1}{2}=\frac{17}{24}[/tex]d)
[tex]\frac{(x+3)+(3x-1)_{}}{2}=\frac{4x+2}{2}=\frac{2(2x+1)}{2}=2x+1[/tex]e)
[tex]\frac{2\sqrt[]{5}+6}{2}=\frac{2(\sqrt[]{5}+3)}{2}=3+\sqrt[]{5}[/tex]