Line segments RQS and TQS are linear equations based on the given equation, because they have a general form of x + y = c. Let the equation for line RQS be y = 2x + 4, and the equation for TQS is y = 6x + 20. Since there is no question written in the problem, I would guess that you want to find the solution of these pair of linear system of equations.
You can do it graphically as shown in the attached picture. Assign random values of x, for which you get corresponding values of y. Plot the x values against y. You would see that the two lines intersect at 1 point. This is the solution of the linear system of equations. It is at point (-4,4).
The other solution is to do it algebraically. Equate the y equations of the lines and then solve for x by transposing like terms.
2x + 4 = 6x + 20
6x - 2x = 4 - 20
4x = -16
x = -16/4
x = -4
Then, use any of the original equations to find y,
y = 2x + 4 = 2(-4) + 4 = -4
The answer is also at point (-4,-4).