Solve the inequality $\frac{x-1}{x-2} \le \frac{3}{2}$.

AlgebraInequalitiesRational ExpressionsInterval Notation
2025/5/26

1. Problem Description

Solve the inequality x1x232\frac{x-1}{x-2} \le \frac{3}{2}.

2. Solution Steps

First, subtract 32\frac{3}{2} from both sides of the inequality:
x1x2320 \frac{x-1}{x-2} - \frac{3}{2} \le 0
Find a common denominator and combine the fractions:
2(x1)3(x2)2(x2)0 \frac{2(x-1) - 3(x-2)}{2(x-2)} \le 0
2x23x+62(x2)0 \frac{2x - 2 - 3x + 6}{2(x-2)} \le 0
x+42(x2)0 \frac{-x + 4}{2(x-2)} \le 0
(x4)2(x2)0 \frac{-(x-4)}{2(x-2)} \le 0
x42(x2)0 \frac{x-4}{2(x-2)} \ge 0
x4x20 \frac{x-4}{x-2} \ge 0
Now, we analyze the sign of the expression. The critical points are x=2x=2 and x=4x=4.
We have three intervals to consider: (,2)(-\infty, 2), (2,4](2, 4], and [4,)[4, \infty).
Case 1: x<2x < 2. Then x4<0x-4 < 0 and x2<0x-2 < 0. Thus, x4x2>0\frac{x-4}{x-2} > 0. So, x(,2)x \in (-\infty, 2).
Case 2: 2<x42 < x \le 4. Then x40x-4 \le 0 and x2>0x-2 > 0. Thus, x4x20\frac{x-4}{x-2} \le 0. So, x(2,4]x \in (2, 4].
Case 3: x>4x > 4. Then x4>0x-4 > 0 and x2>0x-2 > 0. Thus, x4x2>0\frac{x-4}{x-2} > 0. So, x(4,)x \in (4, \infty).
Also, we need to check the endpoints.
If x=4x = 4, 4442=02=00\frac{4-4}{4-2} = \frac{0}{2} = 0 \ge 0, which is true.
If x=2x = 2, the expression is undefined.
Therefore, the solution is x(,2)[4,)x \in (-\infty, 2) \cup [4, \infty).

3. Final Answer

x(,2)[4,)x \in (-\infty, 2) \cup [4, \infty)