The given dimensions of triangle : 4.8 cm, 2.1 cm, and 2.6 cm
The famous triangle inequality says that in any triangle the sum of the lengths of any two sides must be greater than or equal to the length of the remaining side.
But
It means the sum of two sides (2.1 and 2.6) is less than the third side (4.8).
Therefore by triangle inequality, no triangle can be possible by the given measurement.
If the line did pass through that point, then plugging in the point to the equation would be true. But when you plug in 4 for x, the y would be 18, not 15.