Question

①已知方程组｛3x+y=1 x-2y=m的解满足x为正数,求m的取值范围 ②若满足x＞y,求m的取值范围

Answer 1

3x+y=1 x-2y=m

x=(2+m)/7 y=(1-3m)/7

x=(2+m)/7>0

m>-2

(2+m)/7>(1-3m)/7

m>-1/4