18. f-g4, if f =3 and g = -5=

23

Step-by-step explanation:

Step 1:

3 - -5 (4)

Step 2:

3 - (-20)

Step 3:

3 + 20

23

Hope This Helps :)

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.