1. 2b+8-5b+3=-13+8b-5

a negative exponent is translated as follows:

so, we have

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.

the answer is  

d.

121π mi^2

hope you got it chief