ตอบ:
# (- 2 + -2sqrt37) / 9 #
คำอธิบาย:
# 8N ^ 2 + 4n-16 = -n ^ 2 #
# 9N ^ 2 + 4n-16 = 0 #
#N = (- B + -sqrt (ข ^ 2-4ac)) / (2a) #
# = (- 4 + -sqrt (16 + 4 * 9 * 16)) / (2 * 9) #
# = (- 4 + -sqrt (16 + 36 * 16)) / 18 #
# = (- 4 + -sqrt (37 * 16)) / 18 #
# = (- 4 + -4sqrt37) / 18 #
# = (- 2 + -2sqrt37) / 9 #
