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Linear equationsAlgebraMiddle schoolabout 0:55

Solve (x - 1)/4 + (x + 2)/3 = 4: animated lesson

A narrated, step-by-step linear equations video lesson with captions. Final answer: x = 43/7 ≈ 6.1428571.

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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
$\frac{ x-1}{4}+\frac{ x+2}{3} = 4$
2. Step by step
1. $\frac{ x-1}{4}+\frac{ x+2}{3} = 4$
  Start with the equation
2. $\frac{7}{12}x + \frac{5}{12} = 4$
  Simplify each side (distribute and combine like terms)
3. $\frac{7}{12}x = \frac{43}{12}$
  Subtract 5/12 from both sides
4. $x = \frac{43}{12} \div \frac{7}{12} = \frac{43}{7}$
  Divide both sides by 7/12 (multiply by its reciprocal)
3. The answer
$x = \frac{43}{7} \approx 6.1428571$
x = 43/7 ≈ 6.1428571
4. Check
- x = 6.1428571: left side = 4, right side = 4 ✓

Transcript

The problem. Here is the problem: (x minus 1)/4 plus (x plus 2)/3 equals 4. 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). Subtract 5 over 12 from both sides. Divide both sides by 7 over 12 (multiply by its reciprocal).

The answer. So the answer is x equals 43 over 7 approximately 6.1428571. Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves x alone.

Check. x equals 6.1428571: left side equals 4, right side equals 4, which checks out.

About linear equations

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

Solve (x - 1)/4 + (x + 2)/3 = 4: Linear equations Lesson