Question

Jika diketahui nilai x = 3 + √2 dan y = 3 - √20 , maka hitunglah nilai berikut!
a. 2x + y
b. (x + y)²

Answer 1

A.2(3+√2) + 3-√20=
   6+2√2+3-√20=
   9+2√2-2√5
b(3+√2+3-√20)²=
   9+2+9-20=0

Answer 2

A. 2x+y = 2 (3+√2)+3-√20
             = 6+2√2+3-2√5
             = 9 +2 (√2-√5)

b.(x+y)² = (3+√2+3-2√5)²
             = (6+√2-2√5)²
             = 36+2.6.(√2-2√5)+(√2-2√5)²
             = 36+12√2-24√5+2-2.√2.2√5+20
             = 58+12√2-24√5-4√10