The answer is D, none of these.
This is because whole numbers, rational numbers, and integers fit within the category of rational numbers, which is the complete opposite of irrational numbers.
Simplified would be 2a+2b
It is to solve for the 2nd variable. <span />
for number 5, you take the area of the area of the fountain, which is pi * radius squared. this is equivalent to 3.14 * 4^2. then to simplify I made it 3.14 times 16 and then got the answer of 50.24. Then you take the area of the fountain plus the path, which makes the diameter 9.5 divide that by 2 to get the radius, which is 4.75. pi * 4.75^2 is about 70.85. then you subtract the two(70.85-50.24) to get 20.61. since its 10 dollars per square meter, you multiply 20.61 by 10 to get 206.10 dollars. That is your answer.