First rewrite it like this
1. y=5/4x
Then, make X the subject
2.4x=5/y
x=(5/y)÷4
3. Once done, simply replace x with h(x)^-1 and y with x
h(x)^-1= (5/x)÷4
Sorry I'm not very good at rearranging formula but hope this helps :)
Answer:

Step-by-step explanation:
A vector perpendicular to the plane ax+by+cz+d=0 is of the form
.
So, a vector perpendicular to the plane x − y + 2z = 7 is
.
The parametric equations of a line through the point
and parallel to the vector
are as follows:

Put
and 
Therefore,

xy-plane:
Put z = 0 ⇒ t = -2 ⇒x = - 1 , y = 6
So, at point (-1,6,0)
yz-plane:
Put x = 0 ⇒ t = -1 ⇒ y = 5, z =2
So, at point (0,5,2)
xz-plane:
Put y = 0 ⇒ t = 4 ⇒ x = 5, z = 12
So, at point (5,0,12)
<h3>
Answer: 0.557</h3>
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Work Shown:

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Side note:
A similar formula is 
We can isolate the last term to get the first equation shown above.