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Linear equationsAlgebraMiddle schoolabout 0:49

Solve for x: 3x + 13 = -9: animated lesson

A narrated, step-by-step linear equations video lesson with captions. Final answer: x = -22/3 ≈ -7.3333333.

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Video with a synthetic English voice and captions. Pick another language for subtitles in that language, or open the interactive version.

Video narrated by a synthetic voice (Piper TTS, en_US-ljspeech-high voice (LJ Speech dataset, public domain)); the steps come from our maths engine and the answer was checked independently. Download MP4 (0.3 MB) · Captions (WebVTT)

Steps on screen

1. The problem
Solving an equation
$3~ x+13 = -9$
2. Step by step
1. $3~ x+13 = -9$
  Start with the equation
2. $3x = -22$
  Subtract 13 from both sides
3. $x = \frac{-22}{3} = -\frac{22}{3}$
  Divide both sides by 3
3. The answer
$x = -\frac{22}{3} \approx -7.3333333$
x = -22/3 ≈ -7.3333333
4. Check
- x = -7.3333333: left side = -9, right side = -9 ✓

Transcript

The problem. Here is the problem: 3x plus 13 equals negative 9. A linear equation in x: isolate x using inverse operations.

Step by step. Start with the equation. Subtract 13 from both sides. Divide both sides by 3.

The answer. So the answer is x equals negative 22 over 3 approximately negative 7.3333333. Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves x alone.

Check. x equals negative 7.3333333: left side equals negative 9, right side equals negative 9, which checks out.

About linear equations

Solve one-variable linear equations, including ones with brackets and fractions, and check the solution.

Solve for x: 3x + 13 = -9: Animated Step-by-Step Lesson