Question

方程2(X+2)=XY+7的整数解有几组

Answer 1

2(X+2)=XY+7

x = 3/(2-y)

因为3 为质数,所以x只可能= ±1,±3

当x=1时,y = -1

当x=-1时,y = 5

当x=3时,y = 1

当x=-3时,y = 3