We are given a system of two linear equations with two variables $x$ and $y$, and a parameter $m$: $(m+1)x - my = 4$ $3x - 5y = m$ We want to find the values of $m$ for which the system has a solution $(x, y)$ such that $x - y < 2$.
2025/5/26
1. Problem Description
We are given a system of two linear equations with two variables and , and a parameter :
We want to find the values of for which the system has a solution such that .
2. Solution Steps
First, we solve the system of equations for and in terms of .
From the second equation, we can express in terms of and :
, so .
Substitute this expression for into the first equation:
If , then .
Substituting this into the expression for :
.
Now, we have and .
We want , so .
The critical points are and .
We test intervals:
1. $m < -\frac{5}{2}$: $3m + 2 < 0$ and $2m + 5 < 0$, so $\frac{3m + 2}{2m + 5} > 0$.
2. $-\frac{5}{2} < m < -\frac{2}{3}$: $3m + 2 < 0$ and $2m + 5 > 0$, so $\frac{3m + 2}{2m + 5} < 0$.
3. $m > -\frac{2}{3}$: $3m + 2 > 0$ and $2m + 5 > 0$, so $\frac{3m + 2}{2m + 5} > 0$.
Thus, the solution is or .
Also, we assumed , so .