Question

Tolong bantu ya soal ini

Answer 1

A. = 2.(2+√5)+2.(2-√5)
    =4+2√5+4-√5
    =8

b. = 4(2+√5) x (2-√5)
    =(8+4√5) x (2-√5)
    =  16-8√5+8√5-20
    = -4

c. = (2+√5)² + (2-√5)²
    4+5+4-5
    =8

semoga bermanfaat