Final answer:
To solve the system of equations by substitution, we'll solve one equation for x, substitute that expression into the other equation, and solve for y. Then, substitute the value of y back into the first equation to solve for x.
Step-by-step explanation:
To solve the system of equations by substitution, we'll start by solving one of the equations for either x or y and then substitute that expression into the other equation. Let's solve the first equation for x:
x - 4y = 20 => x = 20 + 4y
Now substitute this expression for x in the second equation:
2(20 + 4y) + 5y = 1
Simplify and solve for y:
40 + 8y + 5y = 1
13y = -39
y = -3
Now substitute this value of y back into the first equation to solve for x:
x - 4(-3) = 20
x + 12 = 20
x = 8
So the solution to the system of equations is x = 8 and y = -3.