1⑴x=2 ⑵x=3 ⑶y=-1 ⑷b=-18/5
3⑴x=-4 ⑵y=5/6 ⑶x=4 ⑷y=1/2
4设Ⅰ型洗衣机生产x台,Ⅱ型洗衣机生产2x台,Ⅲ型洗衣机生产14x台,
x+2x+14x=25500
x=1500,2x=3000,14x=21000
5 设宽为xm,长为1.5xm
2﹙x+1.5x﹚=60;x=12,1.5x=18