Answer:
The bigger pizza has a diameter of 14 inches, or a radius of 14 / 2 = 7 inches.
The smaller pizza has a diameter of 12 inches, or a radius of 12 / 2 = 6 inches.
Step-by-step explanation:
The area of a circle is πR2 where R is the radius.
The difference in the size of the pizzas is
Area of bigger pizza - Area of smaller pizza
= π(7 inches)2 - π(6 inches)2 = = 49π inches2 - 36π inches2 = 13π inches2
Micah was asked to add the following expressions:

First, he combined like terms in the numerator and kept the common denominator
First step is correct. He added the like terms in the numerator, because the denominators are same.

So he got , 
In the next step, he cannot cancel out x^2 from the top and bottom . Because x-4 and 3x+2 are added with x^2
If we have x^2 is multiplied with other terms at the top and bottom , then we can cancel out x^2.
So Micah added the expression incorrectly. Final answer is not correct.
Answer: C
.Step-by-step explanation:
it was right for me so if its wrong im sorry :)
I don't think you're stupid. ^^
Let's take the third term, 8. If n=3, then an should be 8.
The first answer gives 15+2.5*3=22.5.
The second answer gives 15.5+2.5=23.
The third answer gives 15-2.5*3=7.5.
The fourth answer gives 15.5-2.5*3=8.
Choice 4 is correct.
Let's try to actually find the equation on our own.
The equation for an arithmetic series is an=a0+dn where a0 is the term that comes before the first term.
The first term given is 13 and it decreases by 2.5 each time so n=-2.5 and the term that would be before 13 is 15.5.
Thus the equation is an=15.5-2.5n