Matematika

Pertanyaan

√(54 + 14√5) + √(12 - 2√35) + √(32 - 10√7)

2 Jawaban

  • Materi : Akar dan pangkat

    Rumus dasar :
    √[a + b + 2√ab] = √a + √b
    √[a + b - 2√ab] = √a - √b

    Pembahasan :
    √(54 + 14√5) + √(12 - 2√35) + √(32 - 10√7)
    = √[54 + 2√(49.5)] + √[7 + 5 - 2√(7.5)] + √[32 - 2√(25.7)]
    = √[54 + 2√245] + [√7 - √5] + √[32 - 2√175]
    = √[49 + 5 + 2√(49.5)] + [√7 - √5] + √[25 + 7 - 2√(25.7)]
    = [√49 + √5] + [√7 - √5] + [√25 - √7]
    = 7 + √5 + √7 - √5 + 5 - √7
    = 12
  • Radicals.

    If a ≥ 0, b ≥ 0, and c ≥ 0, then:
    √(a + b + 2√ab) = √a + √b
    √(a + b - 2√ab) = √a - √b with a > b

    √(54 + 14√5) + √(12 - 2√35) + √(32 - 10√7)
    = √(54 + 2√245) + √(12 - 2√35) + √(32 - 2√175)
    = √[5 + 49 + 2√(5 × 49)] + √[7 + 5 - 2√(7 × 5)] + √[25 + 7 - 2√(25 × 7)]
    = √5 + √49 + √7 - √5 + √25 - √7
    = 7 + 5
    = 12

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