Price of the book = $50
20% discount = 0.2 x 50 = $10
After discount, the price of the book is
$50 - $10 = $40
I have $35, so I need
$40 - $35 = $5 more
Answer: I need to borrow $5 from a friend.
Answer:

Step-by-step explanation:
To find the inverse of a function in equation form, first I recommend changing the f(x) to a y:
y = -6x + 6
Next step is to switch the x and y:
x = -6y + 6
Now solve for the new y:
x - 6 = -6y and

You can put the inverse notation back in for y like I did in the answer section above.
First expand the brackets 18x-12=22x and then you move the 18x to the other side so 12=22x-18x 12=4x. 3=x