How do you solve $(x-1)/x + 7/(3x) = 9/(4x)$ ?

Question

1596 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-10-02T17:23:49

$x = 11/12$

Multiply both sides by $12x$ , (the LCM of x, 3x and 4x)

$12(x - 1) + 7*4 = 9*3$
$12x - 12 + 28 = 27$

Isolate the x

$12x - 12 = 27 - 28$
$12x - 12 = -1$
$12x = -1+12$
$x = 11/12$

Check if the answer doesn't cause an absurd, in this case,
$x != 0$
$3x != 0 rarr x != 0$
$4x != 0 rarr x!= 0$

So the answer is valid.

How do you solve (x-1)/x + 7/(3x) = 9/(4x) (x-1)/x + 7/(3x) = 9/(4x) ?