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

Jun 5, 2016

x=-7

Explanation:

4(x+1)=3(x-1)
4x+4=3x-3
4x-3x=-4-3
x=-7

Jun 5, 2016

$x = - 7$

Explanation:

In the equation $\frac{x + 1}{3} = \frac{x - 1}{4}$, let us first multiply both sides by LCD of $3$ and $4$ i.e. $12$ to eliminate fractions.

Hence this equation can be written as

$\frac{x + 1}{3} \times 12 = \frac{x - 1}{4} \times 12$

$4 \left(x + 1\right) = 3 \left(x - 1\right)$ or

$4 x + 4 = 3 x - 3$

now transposing terms containing variable $x$ to left hand side and constant terms to right hand side, we get

$4 x - 3 x = - 3 - 4$ or

$x = - 7$