15^2 + 25^2 = X62
225 + 625 = x^2
850 = x^2
x = 5sqrt(34)
if you need it as a decimal = 29.1547
First of all, it is 2r

and it would be divide by 3.14 (pi) and then you should have the diameter. Then divide by 2 to find radius.
I believe that it's A neither, because I don't think that it could be displayed on a coordinate graph when it has an exponent in it. So I think it's A. Let me know if I'm correct. ;-)
Cost = fix cost + hourly cost - discount
Cost = 4* [5 + 4x - 4x(20/100)] = 4*[5 + 4x - 0.8x] = 4*[5 + 3.2x] = 20 + 12.8x
Answer: option B) 12.8x + 20
27 ÷ (-2 + (-7))
27 ÷ (-9)
-3
The answer is -3. Hope that helps!