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Example: Evaluating expressions with 2 variables | Algebra I | Khan Academy

  • 0:00 - 0:04
    다음과 같은 식을 풀어봅시다
  • 0:04 - 0:12
    a^2 + 10b - 8
    a는 7이고 b는 -4입니다
  • 0:12 - 0:14
    이 식을 풀려면 먼저
  • 0:14 - 0:19
    a에 7을 대입하고
    b에 -4를 대입합니다
  • 0:19 - 0:20
    왜냐하면 여러분은
    a가 7이고
  • 0:20 - 0:23
    b가 -4일 때를
    계산해야 하기 때문이죠
  • 0:23 - 0:24
    그럼 이제 해봅시다
  • 0:24 - 0:28
    a가 있는 모든 항에
    7을 대입하고
  • 0:28 - 0:35
    그래서 a의 제곱 대신
    7의 제곱을 쓰고
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    같은 색깔로 할게요
    더하기 10 곱하기 b
  • 0:39 - 0:42
    하지만, 여기서 b 대신
  • 0:42 - 0:45
    -4를 대입해서
    식을 계산할 겁니다
  • 0:45 - 0:53
    그래서 10 곱하기 b 대신
    4를 대입하고
  • 0:53 - 0:55
    마지막으로 8를 빼줍니다
  • 0:55 - 0:58
    이제는 이걸
    계산만 하면 됩니다
  • 0:58 - 1:02
    7의 제곱은 49
  • 1:02 - 1:05
    10 곱하기 -4
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    연산순서를 기억하세요
    곱셈이 덧셈보다 먼저입니다
  • 1:08 - 1:10
    이제 이 항을 곱합시다
  • 1:10 - 1:13
    10 곱하기 -4는
    -40입니다
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    식에 -40을 더합니다
  • 1:17 - 1:21
    마지막으로 8을 빼줍니다
  • 1:21 - 1:24
    결론적으로 49 더하기 -40
  • 1:24 - 1:28
    49 빼기 40과도 같죠
  • 1:28 - 1:30
    9가 됩니다
  • 1:30 - 1:32
    이 9에서 8을 빼줍니다
  • 1:32 - 1:34
    그래서 답은 1입니다
  • 1:34 - 1:38
    49 빼기 40은 9에
    8을 빼주면 1입니다
  • 1:38 - 1:40
    이렇게 다 풀었습니다
  • 1:40 - 1:43
    식이 a가 7과 같고
  • 1:43 - 1:46
    b가 -4와 같을 때를
    계산을 한 거죠
Title:
Example: Evaluating expressions with 2 variables | Algebra I | Khan Academy
Description:

Finding Common Denominators

Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/pre-algebra/fractions-pre-alg/equivalent-fractions-pre-alg/e/equivalent_fractions?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra

Watch the next lesson: https://www.khanacademy.org/math/pre-algebra/fractions-pre-alg/comparing-fractions-pre-alg/v/comparing-fractions-with-greater-than-and-less-than-symbols?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra

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https://www.khanacademy.org/math/pre-algebra/fractions-pre-alg/equivalent-fractions-pre-alg/v/equivalent-fractions-example?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra

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Video Language:
English
Team:
Khan Academy
Duration:
01:46

Korean subtitles

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