Lucy is supposed to subtract a certain number from 48 and divide the result by the same number. However, she divided 48 by the same number and subtracted the number from the quotient giving an answer of two. What should be the correct answer?

3 answers

What she was told to do:
(x-48)/x

what she did:
48/x - x = 2

solve for x, then plug into "what she was told to do"

btw, there are two values of x.
my prob is how to find x in the equation

48/x - x = 2

my answer is 6 but i dont know the process of arriving
48/x - x = 2
multiply each term by x to get the quadratic
48 - x^2 = 2x
x^2 + 2x - 48 = 0
(x - 6)(x + 8) = 0

x = 6 or x = -8

btw, What she was told to do should have been:
(48-x)/x

if x = 6,
(48-x)/x = (48-6)/6 = 7

if x = -8,
(48-x)/x = (48 + 8)/-8 = -7