Given that 1/f = 1/u + 1/v , express u in terms of v and f

u = fv/(v - f)

Step-by-step explanation:

1/f = 1/u + 1/v

1/u = 1/f - 1/v = v/fv - f/fv = (v-f)/fv

1/u = (v-f)/fv

u = fv/(v - f)

$X = $12y

Step-by-step explanation:

In this question, we are asked to give an expression to represent the amount of money charged to a man who stayed in a motel for a particular number of days.

Firstly, we need to know the amount of money charged per day. This is visible from

the question and it is equal to $y.

Secondly, the number of days/night stayed is 12 days. This means that the amount of money he was charged is 12 * y = $12y

Since the amount of money charged is equal to $x, the amount to pay can be expressed in terms of y and x to be

$X = $12y