Question

f(x)=
$\frac{4x - 7}{10}$
then what is f^-1(x)​

Answer 1

Answer:

To find f-¹(x) of f(x) equate f(x) to y

That's

f(x) = y

So we have

$y = \frac{4x - 7}{10}$

Next interchange the variables that's x becomes y and y becomes x

That's

$x = \frac{4y - 7}{10}$

Next make y the subject

Cross multiply

We have

4y - 7 = 10x

Move -7 to the right side of the equation

4y = 10x + 7

Divide both sides by 4

We have the final answer as

$y = \frac{10x + 7}{4}$

So

$f ^{ - 1} (x) = \frac{10x + 7}{4}$

Hope this helps you