Question

The function f is defined by f(x)=200÷x−b, where b is a constant. Find b, if the value of f at x= 1/3 is equal to 150.

Answer 1

b = 450

Explanation:

If x equal to 1/3 you substitute 1/3 for x in the equation:

200÷x - b = f(x)

It becomes:

(200÷1/3) - b = f(x)

Then x = 1/3 is also equal to 150, meaning you have to substitute 150 for the f(x).

(200÷1/3) - b = 150.

Then solve in terms of b.

b = 3·200 - 150 = 450

Add b-150.

Simplify!

Answer 2

b = 450

Explanation:

You want b when ...

150 = (200/(1/3)) -b

b = 3·200 -150 = 450 . . . . . add b-150, simplify