Question

Diketahui

a= 3 + √2
a) 2a - 2b

b) 1 + √2 , maka hitunglah
2ab - (a + b)²

Answer 1

1. 2a-2b = 2(3+√2) - 2(1+√2)
=6+2√2 - 2 - 2√2
=4
2. 2ab - (a + b)² = 2((3+√2)(1+√2) - ((3+√2) + (1+√2))²
=2(3+4√2+2) - (3 + 2√2)²
=2(5+4√2) - (17 + 12√2)
= 10+8√2-17-12√2
= -7-4√2
= 7+4√2 (dikali -1)