Factor x^2 - 16x + 64: animated lesson
A narrated, step-by-step expanding and factoring video lesson with captions. Final answer: (x - 8)^2.
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 problemWorked example
- 2. Step by step
- Write the polynomial in standard form
- Recognise a special pattern
- Write the complete factorization
- 3. The answer
x^2 - 16x + 64 = (x - 8)^2
- 4. Check
- Expanding (x - 8)^2 gives back x^2 - 16x + 64.
Transcript
The problem. Here is the problem: x squared minus 16x plus 64. Factor a polynomial over the rational numbers.
Step by step. Write the polynomial in standard form. Recognise a special pattern. The remaining factor is a perfect square trinomial: a squared plus or minus 2ab plus b squared equals (a plus or minus b) squared. Write the complete factorization.
The answer. So the answer is (x minus 8) squared. x squared minus 16x plus 64 factors completely over the rationals as (x minus 8) squared.
Check. Expanding (x minus 8) squared gives back x squared minus 16x plus 64.
About expanding and factoring
Expand products of brackets and factor polynomials completely.
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