Question

$frac{x + 3 }{12} = frac{4 - x}{3}$

Answer 1

$frac{x+3}{12} = frac{4-x}{3}$
$frac{x+3}{12} = frac{4*(4-x)}{12}$
х+3=16-4х
х+4х=16-3
5х=13
х=13:5
х=2,6