m+n+mn=48,求整数m+n=?

Question

如题所述

Answer 1

m+n+mn = 48
m(n+1)+n = 48
m(n+1)+(n+1) = 48+1
(m+1)(n+1) = 49
= 7*7 = (-7)(-7)
= 1*49 = (-1)(-49)
= 49*1 = (-49)(-1)
相应的解有四组，m+n 的值有三个：
m+n = 6+6 = 12
m+n = (-8)+(-8) = -16
m+n = (-2)+(-50) = -52