If you would like to solve the following system, you can calculate this using the following steps:
y = x - 20
y = 6 * x
_________
6 * x = x - 20
6 * x - x = -20
5 * x = -20 /5
x = -4
y = 6 * x = 6 * (-4) = -24
If you would like to solve the following system, you can calculate this using the following steps:
y = x + 20
y = 6 * x
_________
6 * x = x + 20
6 * x - x = 20
5 * x = 20 /5
x = 4
y = 6 * x = 6 * 4 = 24
The actual inverse function is:

And the domain is [0, ∞).
<h3>
Where is the mistake?</h3>
Remember that for a given function f(x) with a domain D and a range R.
For the inverse function, f⁻¹(x) the domain is R and the range is D.
Here, for the given function the domain is x ≥ 3 and the range is [0, ∞).
Then for the inverse function, which is:

(to check this, you must have that):

The domain will be [0, ∞) and the range x ≥ 3
If you want to learn more about inverse functions:
brainly.com/question/14391067
#SPJ1
Its a graph linear i believe