算一下一下题目: (1)-2⼀3(x+1)>-2 (2)[(2x+1)⼀-2]-[(x-3)⼀3]>2 (3)(2x-3)⼀-3>(-3x-2)⼀2 要过程

2025-01-05 16:58:48
推荐回答(2个)
回答1:

(1)[(2x-1)/3]-[(5x+10]≤1
2x-1-3(5x+10)≤3
2x-1-15x-30≤3
-13x≤34
x≥-34/13
(2)[(3x-2)/3]-[(9-2x)/3≤【(5x+1)/2】
(5x-11)/3≤(5x+1)/2
2(5x-11)≤3(5x+1)
10x-22≤15x+3
-5x≤25
x≥-5
(3)1/2(x-1)<1/3-2x
3(x-1)<2-6x
3x-3<2-6x
9x<5
x<5/9
(4)1/2[x-1/2(x+1)]≤2/5(x-1)
1/2[1/2x-1/2]≤2/5x-2/5
1/4x-1/4≤2/5x-2/5
5x-5≤8x-8
-3x≤-3
x≥1
(5)3(x+1)/8+2<3-(x-1)/4
3(x+1)+16<24-2(x-1)
3x+3+16<24-2x+2
5x<7
x<1.4
(6)(0.4x+0.9)/0.5-(0.03+0.02x)/0.03>(x-5)/2
(4x+9)/5-(3+2x)/3>(x-5)/2
6(4x+9)-10(3+2x)>15(x-5)
24x+54-30-20x>15x-75
-11x>-99
x<9

回答2:

(4)1/2[x-1/2(x+1)]≤2/5(x-1)
1/2[1/2x-1/2]≤2/5x-2/5
1/4x-1/4≤2/5x-2/5
5x-5≤8x-8
-3x≤-3
x≥1
(5)3(x+1)/8+2<3-(x-1)/4
3(x+1)+16<24-2(x-1)
3x+3+16<24-2x+2
5x<7
x<1.4
(6)(0.4x+0.9)/0.5-(0.03+0.02x)/0.03>(x-5)/2
(4x+9)/5-(3+2x)/3>(x-5)/2
6(4x+9)-10(3+2x)>15(x-5)
24x+54-30-20x>15x-75
-11x>-99
x<9