5x-6=5/6+7y x/3=1+y/2解这个不等式组,
问题描述:
5x-6=5/6+7y x/3=1+y/2解这个不等式组,
答
5x-6=5/6+7y .(1)
x/3=1+y/2.(2)
(1)式两边同乘以6 得 30x +42y = 41.(3)
(2)式两边分别同乘以(6* 15)和(6* 14)得30x+ 45y= 45.(4)
28x+ 42y= 42.(5)
(4) - (3)得 3y = 4 则 y = 4/3
(3) - (5)得 2x = - 1 则 x = - 1/2