12+2х<0

To solve the inequality \( 12 + 2x < 0 \), follow these steps:

1. Subtract 12 from both sides: \[ 2x < -12 \]

2. Divide both sides by 2 (noting that since 2 is positive, the direction of the inequality stays the same): \[ x < -6 \]

So the solution to the inequality \( 12 + 2x < 0 \) is: \[ x < -6 \]

In interval notation, this can be expressed as \( (-\infty, -6) \).