1. y1 + y2 = 25
5 + 2*y1 = 40 + y2
解聯(lián)立方程得
y1 = 20
y2 = 5
2. y = y1 + y2
MC = MC1 = MC2 = (MC1 + 2*MC2)/3 = [(5+2*y1) + 2*(40+y2)]/3
MC = 85/3 + 2*y/3MC = MC1 = MC2 = (MC1 + 2*MC2)/3 = [(5+2*y1) + 2*(40+y2)]/3 為什么 MC= (MC1 + 2*MC2)/3 ？ 還有，可不可以，先算出反函數(shù)，y1=MC1/2-2.5 ，y2=MC2-40然后，y1+y2=MC1/2+MC2-42.5 然后，，，我就不知道怎么樣弄回MC了，因?yàn)橛袃蓚€(gè)MC，一個(gè)MC1、MC2有一條代數(shù)定理，大概是初中學(xué)的，是這樣的：如果a/b = c/d，則a/b = (a+c)/(b+d)。用在MC1 = MC2，設(shè)a = MC1b = 1c = 2MC2d = 2則MC1 = (MC1+2MC2)/(1+2) = (MC1+2MC2)/3用你的方法，記住MC1 = MC2 = MCy = y1 + y2 = (3/2)*MC -42.5解MCMC = 85/3 + 2*y/3