Final answer:
The solution to the system of linear equations 2x - y = 23 and 4y = -20 is found by using substitution method. First, solve for y in the second equation, which gives y = -5. Then substitute y in the first equation to solve for the value of x, resulting in the solution (9, -5).
Step-by-step explanation:
To solve the system of linear equations by substitution, we can start by solving one of the equations for a single variable, and then substituting that expression into the other equation. Here, we have the system:
First, we solve the second equation for y:
4y = -20 ⇒ y = -5
Next, we substitute -5 for y in the first equation:
2x - (-5) = 23 ⇒ 2x + 5 = 23
Now, we solve for x:
2x = 23 - 5 ⇒ 2x = 18 ⇒ x = 9
Therefore, the solution to the system of equations is (x, y) = (9, -5).