问题
解答题
计算 (1)-14-|-2|+
(2)解不等式组:
(3)下课了,老师给大家布置了一道作业题:当x=1+
|
答案
(1)原式=-1-2+2÷4=-3+
=-21 2
;1 2
(2)
,-3(x+1)-(x-3)<8①
-2x+1 3
≤1②1-x 2
由①得:x>-2,
由②得:x≤1,
∴原不等式组的解集为:-2<x≤1,
∴它的整数解为:-1,0,1,
∴它的整数解的和为:-1+0+1=0;
(3)
÷(1+(x2-1)(x+1) x2-x
)=x2+1 2x
÷(x-1)(x+1)2 x(x-1)
=x2+2x+1 2x
•(x-1)(x+1)2 x(x-1)
=2.2x (x+1)2
∴当x=1+
时,原式=2.3