The image you uploaded seems to contain a math problem in Vietnamese. It appears to involve coordinate geometry, specifically with lines and points in the plane. The problem also includes the equation of lines and geometric relationships involving a triangle.

Here's a summary of the problem as I understand it:

• We are given two lines:
  • Line $d_1$: $x - y - 1 = 0$
  • Line $d_2$: $2x + y - 5 = 0$
• Point $M(1, -1)$ lies on a third line $d$, which intersects both $d_1$ and $d_2$ at points $B$ and $C$.
• The triangle $ABC$ has the condition $BC = 3AB$, and the equations of lines $BC$ and $AB$ are in the form:
  • $ax + y + b = 0$ (for line $BC$)
  • $cx + y + d = 0$ (for line $AB$)

The task seems to involve finding the value of $T = a + b + c + d$.

To solve the problem, the following steps should be taken:

1. Find the intersection points of the lines $d_1$ and $d_2$, which will help to find the coordinates of $A$.
2. Determine the equation of the line $d$ passing through $M(1, -1)$, and its intersection points $B$ and $C$.
3. Use the condition $BC = 3AB$ to establish a relationship between the coordinates and solve for the required values.

Would you like to go through this step by step, or is there any specific part you'd like to focus on?