No not rational because you cant divide it
Answer:
The second and the last options.
Step-by-step explanation:
15/ 2/9 =67.5 Solve the original problem
15*2/9 =3.33333333333
15*9/2 =67.5
(15* 1/9) /2=0.833333333333333
15*9* 1/2 =67.5
Answer:

Step-by-step explanation:
Here,
f(x) = y

or , swapping x with y

now to solve for y we get

now we put f inverse x instead of y

I am done.
Because a rectangular pyramid's base is square, the cross section would be as well
82/4+20-15
82:4=20.5
20.5+20=40.5
40.5-15=25.5