✔ 最佳答案
1900 (1.08)^z = 800(1.14)^z
divide both sides by 800
19/8 (1.08)^z = (1.14)^z
divide both sides by (1.08)^z
19/8 = (1.14)^z / (1.08)^z
19/8 = (1.14/1.08)^z
log(19/8) = z log(1.14/1.08)
divide both sides by log(1.14/1.08)
log(19/8) / log(1.14/1.08) = z
z = 15.9986