algebra expression

Question

if x+1/x=4 find  x^2-1/x^2

Answer 1

part 1...(x+1)/x=4

x+1=4x

3x=1

x=1/3

##### part 2

mi ges: it spozed tu be (x^2 -1)/x^2

x^2=1/9=0.11111

x^2-1=-8/9

divide bi 1/9=multipli bi 9

anser=-8

Answer 2

Chloe is having a birthday party the cost of hiring the hall is £20 plus a booking fee of £12 write an expression to show the cost of hiring the hall