∵m²-5m - 1 = 0∴5m = m² - 1 -------------------①m1 + m2 = 5m1xm2 = -1∴m1² + m2² = 27 设2m²-5m+1/m² = x -----------------------②由①②得(m²)² + (1-x)m² + 1 = 0(m1)² + m2² = x - 1∴x = 28
2m2-5m+1/m2 =28