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Linear equationsAlgebraMiddle schoolabout 0:37

Solve 3a + 4 = 19: animated lesson

A narrated, step-by-step linear equations video lesson with captions. Final answer: a = 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 (0.2 MB) · Captions (WebVTT)

Steps on screen

1. The problem
Solving an equation
$3~ a+4 = 19$
2. Step by step
1. $3~ a+4 = 19$
  Start with the equation
2. $3a = 15$
  Subtract 4 from both sides
3. $a = \frac{15}{3} = 5$
  Divide both sides by 3
3. The answer
$a = 5$
a = 5
4. Check
- a = 5: left side = 19, right side = 19 ✓

Transcript

The problem. Here is the problem: 3a plus 4 equals 19. A linear equation in a: isolate a using inverse operations.

Step by step. Start with the equation. Subtract 4 from both sides. Divide both sides by 3.

The answer. So the answer is a equals 5. Doing the same operation to both sides keeps the equation balanced. Undoing addition, then multiplication, leaves a alone.

Check. a equals 5: left side equals 19, right side equals 19, which checks out.

About linear equations

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

Solve 3a + 4 = 19: Linear equations Step-by-Step Lesson