Question

Q.ulQaz

Jika diketahui, a = 4√3 - √5 dan b = 2√5 + √3, maka nilai dari ab = ... ​

Answer 1

a = 4√3 - √5

b = 2√5 + √3

maka :

ab

a × b

( 4√3 - √5 ) ( 2√5 + √3 )

4√3 ( 2√5 + √3 ) - √5 ( 2√5 + √3 )

8√15 + 4√9 - 2√25 + √15

8√15 + 4(3) - 2(5) + √15

8√15 + 12 - 10 + √15

8√15 + 2 + √15

8√15 + √15 + 2

(8+1)√15 + 2

9√15 + 2

Answer 2

SOAL 1

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a → 4√3 - √5

b → 2√5 + √3

___________________________________________ a × b

= 4√3 - √5 × 2√5 + √3

= 4√3(2√5 + √3) - √5(2√5 + √3)

= (4 × 2)√(3 × 5) + 4(3) - 2(5) + √(3 × 5)

= 8√15 + 12 - 10 + √15

= (8√15 + √15) + (12 - 10)

= (8√15 + 1√15) + (12 - 10)

= 9√15 + 2

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