n^2 + n = 1/2 n adalah...

n² + n = 1/2 ... kalikan 2
2n² + 2n - 1 = 0

Dgn rumus abc
n1.2 = (-b ± √(b² - 4ac))/2a
n1.2 = (-2 ± √(4 + 8))/(2.2)
n1.2 = (-1 ± √3)/2

Nilai n
n1 = (-1 + √3)/2
n2 = (-1 - √3)/2