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Linear equationsAlgebraMiddle schoolabout 0:50

Solve (x + 7)/5 + (x - 7)/5 = -9: animated lesson

A narrated, step-by-step linear equations video lesson with captions. Final answer: x = -45/2 ≈ -22.5.

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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
$\frac{ x+7}{5}+\frac{ x-7}{5} = -9$
2. Step by step
1. $\frac{ x+7}{5}+\frac{ x-7}{5} = -9$
  Start with the equation
2. $\frac{2}{5}x = -9$
  Simplify each side (distribute and combine like terms)
3. $x = -9 \div \frac{2}{5} = -\frac{45}{2}$
  Divide both sides by 2/5 (multiply by its reciprocal)
3. The answer
$x = -\frac{45}{2} \approx -22.5$
x = -45/2 ≈ -22.5
4. Check
- x = -22.5: left side = -9, right side = -9 ✓

Transcript

The problem. Here is the problem: (x plus 7)/5 plus (x minus 7)/5 equals negative 9. A linear equation in x: isolate x using inverse operations.

Step by step. Start with the equation. Simplify each side (distribute and combine like terms). Divide both sides by 2 over 5 (multiply by its reciprocal).

The answer. So the answer is x equals negative 45 over 2 approximately negative 22.5. Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves x alone.

Check. x equals negative 22.5: 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 (x + 7)/5 + (x - 7)/5 = -9: Linear equations Lesson