Which function below is the inverse of f(x)=7x-1/2

We write f(x) in terms of y I.e y=7x-1/2.

Fractions are sometimes ambiguous, we eliminate the fraction by multiplaying the entire function by 2.so as to get 2y=14x-1.

Make x the subject, x=2y+1/14,

Thus the inverse f(x)=2x+1/14

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk

it would open into a square depending on the type of envelope i’m not sure about the second part