Question

Soal olim math yg dilaksanakan oleh UB 2017

jika diket 2/a - 2/b = 1 dan b - a = 2 maka (a+b)^2 = ...

a) -20
b) -12
c) 4
d) 12
e) 20

Answer 1

Verified answer

2/a - 2/b = 1
maka
2b - 2a / ab = 1
ab = 2b-2a
ab = 2(b-a) = 2(2) = 4

(b-a = 2)²
b² - 2ab + a² = 4
a² + b² = 4 + 2ab = 4 + 8 = 12

(a+b)²
= a² + 2ab + b²
= 12 + 8
= 20

=>>> E