Question

Tentukan hasil kali bilangan bentuk akar di bawah ini :
1. ( √5 + √2 ) (√5 - √2 )
2. ( 3√5 - 4√3 ) ( 3√5 - 4√3 )
3. ( 2√3 + √5 ) ( √6 - √15 )
4. ( 4√2 + 2√8 )²

Answer 1

1. =√25 - 2√5 + 2√5 - √4
=5 - 2
=3
maaf jika salah.

Answer 2

1)
(√5+√2).(√5-√2)
= √5.√5+√5.(-√2)+√2.√5+√2.(-√2)
= √25-√10+√10-√4
= 5-2
= 3

2)
(3√5-4√3).(3√5-4√3)
= 3√5.3√5+3√5.(-4√3)+(-4√3).3√5+
(-4√3).(-4√3)
= 9√25-12√15-12√15+16√9
= 9.5-24√15+16.3
= 45-24√15+48
= 93-24√15

3)
(2√3+√5).(√6-√15)
= 2√3.√6+2√3.(-√15)+√5.√6+
√5.(-√15)
= 2√18-2√45+√30-√75
= 2√(9.2) - 2√(9.5) + √30 - √(25.3)
= 2.3√2 - 2.3√5 + √30 - 5√3
= 6√2 - 6√5 + √30 - 5√3

4)
(4√2 + 2√8)²
= (4√2)² + 2.4√2.2√8 + (2√8)²
= 16√4 + 16√16 + 4√64
= 16.2 + 16.4 + 4.8
= 32 + 64 + 32
= 128