解:
去分母得:5(x﹣1)=20﹣2(x+2),
去括号得:5x﹣5=20﹣2x﹣4,
移项合并得:7x=21,
解得:x=3.
25____24 55____65 100____99 78____87
44____33 68____86 60+6____29 24____20+4
56____50+4 86-80____7 55-5____50 43____34
(Ⅰ)求角B的大小;
(Ⅱ)求 3 sinA+sin(C﹣ π6 )的取值范围.